Talk:Primary color

Psychological Primary Colors

I'm surprised that this article doesn't explain the Psychological Primary Colors. Please put so in whatever article they are appropriate for. They were not invented by any Wikipedian; they are mentioned at http://dictionary.reference.com at "primary color", and at several Internet sites, as you can see by doing a Google search. 66.32.126.20 21:30, 3 Apr 2004 (UTC)

Old talk

"This is also lends some insight into why visible-light lasers tend to be only red, green, or blue. using combinations of colors creates frequency interference, causing the beam to become decollinated and to spread apart quickly. (But does it explain why lasers aren't orange, yellow, or cyan? Those colors can also be created with one wavelength.)"

There is nothing fundamental about these colors, they're just wavelengths. Color is arbitrarily determined by in the eye, depending on the intensity of the signal in one of the six different types of cone groups. For a quick proof by counterexample, the maser was invented before the laser (maser stands for Microwave Amplification by Stimulated Emission of Radiation, and has no color whatsoever)--BlackGriffen

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I also removed:

This is the reason that television uses red, green, and blue phosphors. Any color combination can be represented by mixing different proportions of the primary colors. Note that in practice this is restricted by technical limitations of the medium, for example the television standard NTSC is noted for its inability to represent certain colors to retain backward compatibility with black and white televisions.

This isn't true at all. There's really no such thing a "primary" and "non-primary" color--the primaries are just whichever ones you choose to call primary, and the colors they can make with mixing are only those within the gamut of those your choose. Some make better choices than others, but let's not make it sound like there's some special property of red, green, and blue that make them magical or something. --LDC

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What makes red, green, and blue special is that they correspond to the peak responses for the human eye's photoreceptors. Is that right? --Damian Yerrick

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Well, yes, there is that. But the primaries typically chosen for TVs and such don't correspond exactly to the peaks of the cones' responses, but to colors that are pretty close and that have cheap available phosphors. And you really can stray pretty far from the actual human visual primaries and still get a good gamut. And non-human eyes may have entirely different primaries--birds have four, for example. --LDC

Red, green and blue are not the peak responses. The wavelengths of the peak responses are given in the color article. You choose red, green and blue light because you get the biggest part of the human color space that way. Red light for instance is lower in frequency than the "red" cone's peak frequency in the eye so that it won't create a response in the "green" cone (the cone's response curves overlap). There is a definite biological reason why red, green and blue light are the additive primaries for human color vision, but it's not the peak responses.AxelBoldt

Primaries in L*a*b space

On the diagram at color under 'CIE XYZ color space', the colors around the outside of the horseshoe shape (but not the bar that links the two ends) are colours that appear in the rainbow. That is, they can be made of light of a single wavelength. This makes them a bit special, and could be the basis for calling them primary. They cannot be made by mixing any other single-wavelength colors. The colors in the middle (which would include the colors of phosphors used in television) can be made by mixing pure-wavelength light (or colors from the outside of the horseshoe). The colors on the bar that links the two ends of the horseshoe are sometimes called 'imaginary colors', as they don't appear in the rainbow, and there is no single wavelength light of those colors. They must be made by mixing the blue and red wavelengths at either end of the rainbow.

The "primaries" in XYZ space are beyond the range of human vision. In other words, they are purely imaginary. --jacobolus (t) 22:24, 22 April 2007 (UTC)

Ok for the hundredth time

And you are are very cose to correct but listen carefuly, cause it's confusing: Additive color is not a color space. RGB of given colors can be a color space. So you can say a such and such RGB is a color space which uses the additive color system..yadda yadda So you can say a such and such CMYK is a color space which uses the subtractive color system..yadda yadda

So ya almost got it

I'm getting the page entitled Subtractive color space deleted by the admins, 'cause it's just plain wrong. We willl eventually have a lovely page describing the subtractive color system.

Am I making sense?

It's subtle, but crucial--Dkroll2 02:51, Dec 27, 2004 (UTC)

Color and Color vision is a simple task to describe.

color

I havent' a clue what ya'll have done to this definition but it's been taken to the far side. Color and Color vision is a simple task to describe. Just do that, I can't believe all the techno mumbo jumbo which belongs somewhere else. I'm saying to delete the visible spectrum or the rods and cones, but red it and imagine you are coming there wanting to know how color works, and maybe link to a section on how to control it/standardize/quantify it. Too much in one place just for a tiny word "color" IMHO Love ya smarties anyway --Dkroll2 06:37, Dec 27, 2004 (UTC)

Wikiproject Color

I'm looking to start up Wikipedia:WikiProject_Color again. It seems to have been dormant for a while, even though there was a lot of great work and discussion already done. Anyone care to join me? --Laura S 01:31, 19 May 2006 (UTC)

The term vector basis may be improper

Hello. In the introduction, we have:

If the color space is considered as a vector space, the primary colors can be regarded as a set of basis vectors for that space.

but I think it is not mathematically correct. If the color space is of dimension 3, then any three linearly independent colors would make a set of basis vectors, even if they are not primary colors. Probably primary colors would be better defined has extreme points of a convex set, or perhaps generative vectors of a convex cone. --Bernard 17:36, 22 September 2006 (UTC)

No, basis vectors is exactly right. Any three linearly-independent colors can be called primary colors. There is absolutely nothing special about the primaries in widespread use. --jacobolus (t) 22:26, 22 April 2007 (UTC)

To follow up, no 3 colors can be mixed to produce all other possible colors. In fact, most spectral colors (single wavelength) cannot be produced in a second way. The only way to mix all colors as a combination of three primaries is to make the primaries imaginary, beyond the range of human vision, as in CIE XYZ. --jacobolus (t) 22:28, 22 April 2007 (UTC)

In other words, it's not a vector space. The gamut is a convex set and the area covered by a set of primaries is a convex cone, as he said. 86.5.99.20 12:13, 14 October 2007 (UTC)

Oh, okay. You might be right. I'm realizing I don't have a precise understanding of the mathematical properties of the space of human vision—that is, what the effect is of making e.g. some spectral light source arbitrarily bright. Given that there is indeed some point beyond which additional intensity cannot be detected (or maybe it just fries your eyeballs at that point :), scalar multiplication doesn't necessarily hold for a large enough scalar, which would make us have not a vector space. But anyway, in the vector space of which the gamut of human vision is a subset, any three colors can be considered a bases for the space… so the description in the article is still fine I'd say. --jacobolus (t) 15:38, 14 October 2007 (UTC)

Jacobolus wrote "The only way to mix all colors as a combination of three primaries is to make the primaries imaginary". That's not true. The other way is to allow negative coefficients in the linear combinations. It's a vector space, in theory, if you do not impose gamut limits, and this is what is meant in "If the color space is considered as a vector space". A gamut is then a region in this vector space (probably convex, but not necessarily so). It's important to keep clear the distinctions between mathematical colorimetric, human perception limits, device limits, etc. Within mathematic colorimetry, it's very clear what is meant by vectors, imaginary colors, etc. Dicklyon 17:06, 14 October 2007 (UTC)

Well, we're no longer mixing real lights at the point where some coefficients are negative. :) But right. --jacobolus (t) 22:11, 14 October 2007 (UTC)

True; if you make that restriction to positive coefficients, that's when you get a gamut that doesn't cover all colors. That's still a region in a vector space. Dicklyon 22:52, 14 October 2007 (UTC)

It might be worth pointing out that a convex set is a region in a vector space.Neodymion (talk) 17:52, 27 June 2008 (UTC)

Gendale?

I believe this is a newly discovered primary color. Shouldn't it be mentioned somewhere on this page?24.234.170.197 02:15, 5 October 2006 (UTC)

Gendale is a joke, isn't it? From what I have seen on the web, it seems to be an impossible color --Bernard 19:10, 9 October 2006 (UTC)

Primary Colour or Colour?

I found the page by typing 'primary colour' and in the first paragraph it said 'A primary colour or colour'. I found the page again by typing 'primary color' and the introductory paragraph said 'A primary color or color'. Why does it say this?--Jcvamp 13:59, 11 December 2006 (UTC)

Maybe it is some Wikipedian who allowed this to work, but I HAVE NO IDEA HOW THIS IS POSSIBLE. Georgia guy 14:43, 11 December 2006 (UTC)

B Class in wikiproject color?

This article has no introduction, is full of claims of dubious scientific merit, and has almost no relevant citations. It does not discuss the history of primary colors, or their historical application to paint mixing. It does not show any chromaticity diagrams with labeled primary color gamuts. It does not give the reader a clear understanding of the idea of a primary color, and it does not put that idea in its pre-20th-century historical context. I think I would classify this "start" class. --jacobolus (t) 22:45, 22 April 2007 (UTC)

Muddy brown

Just a question for the color experts here, and something that might be a nice addition to the article. The article mentions that "in theory" full combinations of saturated cyan, magenta, and yellow should produce black but that they don't. Is this because most light is not precisely white? If this is the case, it might be nice to point that out as the reason why for readers. If that's not the reason, does anyone know what is? —Preceding unsigned comment added by Troped (talk • contribs)

Of the numerous references that repeat this comment, I only found a reason given in one, and it was wrong, so I won't bother quoting it. The problem is that the inks tend to be in layers, and the upper layers will reflect some light before giving the lower layers a chance to absorb it. If yellow is on top the result will be brown, but for other orders it will be some other off-black muddy color. Dicklyon 18:10, 8 June 2007 (UTC)

Also light is very rarely white, but the human brain adjusts to tell the color of something regardless of the light. For example, indoor light bulbs are usually very yellow -- —Preceding unsigned comment added by 209.247.23.35 (talk)

White is not a well-defined color for light. When using incandescent light, the color of the light is usually taken as white, or the illuminant white point, even though this white is yellower than some other whites. So saying "light is very rarely white" is essentially meaningless. Dicklyon 18:27, 19 June 2007 (UTC)

tetrachromats

Is there any evidence (i.e. actual psychological experiments on birds, neurological arguments, or even speculation from reputable biologists, etc.) that species with four types of cone responses actually have vision which can be modeled in a four-dimensional space, or is this just a speculative extension of the three cone types → three-dimensional color vision that we humans have? I don't notice any cited sources for this claim. If not, I'd like to remove such claims, or at least eliminate the certainty with which they are stated in this article. If so, I'd like to see a better explanation, and some citations. --jacobolus (t) 01:14, 26 June 2007 (UTC)

Also, it should be made clear that the three-dimensional models for trichromatic color are also just rough approximations, based on very strict assumptions. Color vision seems to be much more complex than any simple mathematical models, so this whole article is just a useful abstraction, not necessarily a direct representation of reality. --jacobolus (t) 01:44, 26 June 2007 (UTC)

Okay, actually an academic paper linked from the tetrachromacy article says the following:

One further modeling improvement supposes that the additional photopigment serves two different functions. First, the fourth pigment may possibly be serving as a normal pigment variation that is integrated into a standard three-dimensional structure of metameric classes (thus, heterozygotes with four-photopigment classes expressed are not discernible on the basis of color-matching measures). Second, the fourth pigment may also feed some higher order (probably cortical) mechanisms that take advantage of the signal from the fourth pigment for color discrimination in a way that differs from judging metameric class equivalences. This second possibility is not unlikely since, in other species, wavelength information can be used for various perceptual tasks quite independently from the structure of metameric color codes. That is, color vision and wavelength-dependent behavior can independently coexist in the same animal (e.g., bees exhibit trichromatic color vision exclusively in feeding and in recognition of the hive, while, at the same time, using spectrally narrow-band receptor channels for a variety of other tasks, such as celestial orientation and navigation; see Menzel, 1985, for a discussion). Thus, one might venture the speculation that the present results indicate that the fourth pigment—though it seems to merge with trichromatic equivalence classes of primary codes—is exploited by independent mechanisms that deal with the discrimination of border discontinuity and the like. Such architectural implications very much resemble those from studies on cortical colorblindness, or achromatopsia (Stoerig, 1998; Troscianko et al., 1996).

Which implies to me that the ramifications are not precisely known, and these statements about four-dimensional spaces are speculative, without a rigorous experimental justification. So that should be reflected in the article, I think. --jacobolus (t) 02:48, 26 June 2007 (UTC)

Good idea. I also haven't seen evidence of true tetrachromacy, though I wouldn't be surprised.

References

I cleaned up a bunch of misinformation, and found refs for most of what remains. Feel free to add more, or call for more citations on questionable info, or add more info. But don't add unsourced info: look it up, please. Dicklyon 06:42, 26 June 2007 (UTC)

Yellow and Blue make green

If you mix yellow paint with blue (blue, not cyan) paint you get green paint. The subtractive colour model does not account for this (try it, you get black), so why does it happen?

Red, Yellow and Blue are the traditional artistic primary colours, and they don't get a mention here, this is wholly different to the CMYK model. Its all too computer biased here with no basic artistic foundations. —Preceding unsigned comment added by 81.99.38.101 (talk)

I suggest you read this link and this one, and perhaps look at this picture as well. Indeed this article isn't nearly as comprehensive as it should be. You're right that yellow and blue (though usually closer to "cyan" than "blue") paints mix to a rather unsaturated green. I don't think anything in this article contradicts that, however. What happens is that paint mixtures don't go along straight lines in a color space like CIELab or CIECAM02, but along curved paths, in this case bowing out towards the green. To get rich greens though requires using green pigments. See this picture which shows fairly unsaturated mixtures of blue and yellow paints on the top row, as compared to brighter green paints on the bottom row (and obviously the exact effect can't be accurately seen on a computer monitor; the distinction between top and bottom rows would appear if anything more dramatic on paper). --jacobolus (t) 01:11, 31 July 2007 (UTC)

To be clear though, this article should certainly discuss "traditional artistic" colors, and discuss their historical changes as new pigments became cost-effective, etc., and should preferably roughly locate the "Red", "Yellow", and "Blue" intended in a color space like CIELab or similar, so that readers can have a better understanding of which colors specifically are meant by each of these descriptions. --jacobolus (t) 01:29, 31 July 2007 (UTC)

Secondary Colors are not Primary colors

I thought it was a fairly simple concept that a palette named the "secondary palette" was not, and did not claim to be, limited to primary colors, I also noticed that the palllate at the cited web page does not match the one listed here, so I'll be modifying that section.

Please do not start a revert war, thank you.67.34.196.115 16:55, 15 August 2007 (UTC)

“Primary” colors are a human construct. A “split primary” palette also does not include “perfect primaries” in the eyes of the 18th-19th century color theorists who developed the idea of material trichromacy. By my definition any color which is used in a palette which cannot be mixed from the other colors of that palette is sufficiently “primary”. If you like, we can change this word to something less controversial (controversial in the 19th century perhaps…). Anyway, you still borked the citation format, changed the meaning of the article, and reverted several changes unrelated to the issue you care about. Before reverting again, please get a concensus on this talk page. Thanks. Also, consider making your own user page, so we don't have to refer to you by number. --jacobolus (t) 17:06, 15 August 2007 (UTC)

I've changed the sentence slightly to clarify. --jacobolus (t) 17:14, 15 August 2007 (UTC)

Just because something is a human construct does not make it valid to simply disregard its internal logic, the website your citing does not provide support for the statement its being used as a source for, first off red is not part of the secondary palette explained at the source, secondly the author does not call most of the colors on this palette primaries or even "primaries" the whole point is that it rejects the idea of primary colors altogether. If its that big a deal to keep it here I'll change it in a more conservative manner.

As for consensus so far you and I are the only people whove said anything about it one way or the other, I know becuase I listed RYB here in the first place and I've been watching it, this is a new section and any edits to it are essentially new changes to this page.

Velps 18:04, 15 August 2007 (UTC)

No, but the point is that artists who use “primary colors” as a means of organizing their thoughts about color are oversimplifying, and relying on a model that imposes real costs on colorfulness of “non-primary” hues. Thus some artists instead use 6 (or more) colors, evenly-spaced around a “color wheel”, to reduce those costs. To change the link and wording as you did undermines that message (which is the reason that I originally wrote that sentence as I did). But equally, the problem was that you several times reverted unrelated changes, and damaged the formatting of the page, in your quest to revert to the version that you approved of, even after it had been pointed out. I've made one more fix to the sentence… see if that does it for you. --jacobolus (t) 18:12, 15 August 2007 (UTC)

And note, the RYB color model article as it stands a) is poorly explained, b) contains quite a bit of unsubstantiated nonsense, c) is unsourced, d) has diagrams which obscure as much as they illuminate. It needs to have a solid historical section written, a much more thorough explanation of the gamut which can be made by RYB paints, with some solid diagrams, and a critical review section at the end which explains why it is no longer particularly useful, in light of newer and more perceptually-accurate models. I fixed the summary posted to this page (primary colors) to no longer contain nonsense, but I don't really have the time or energy to fix up the RYB color model page. --jacobolus (t) 18:18, 15 August 2007 (UTC)

I don't see how the validity or invalidity of the concept of primary colors or RYB color space in general has any bearing on the part of this section we're talking about, when I said I listed RYB here, I ment here in this particular article, RYB has historical importance and exists as a concept. In any event I've edited the section in a less severe way which is also supported by the cite hopefully this will be satisfactory for everyone Velps 18:25, 15 August 2007 (UTC)

No. A palette with 6 colors is not 3 “primaries” and 3 “secondaries”. There is absolutely nothing special about three of the colors as opposed to the other three. You'll note that if there was, the three “primaries” according to this palette would then by cyan, yellow, and magenta. I really suggest you read this page before continuing to edit the page. It will hopefully give you a better understanding of so-called “primary” colors. --jacobolus (t) 18:31, 15 August 2007 (UTC)

There is nothing objectively special about them, and while you may, perhaps rightly, feel that all the colors on the secondary palette deserve to be called primaries, they're not, that's why its called the secondary palette. I'm not particulary interested in the scientfic or practical value of RYB with regard to this particular point.

Please keep in mind I'm only calling them notional secondary colors.

I also think you're relying way too much on this handprint website and starting to make an argument rather than convey information in a NPOV non-OR way. Velps 18:58, 15 August 2007 (UTC)

Listen, the point of the sentence is to explain the limitations of relying on primary-color models, which happen to be bad models for a variety of reasons. If you leave out such explanation, the article endorses the ideas that RYB is good for painting, which is most certainly NPOV. Frankly, several more sections should be added to this primary color article, explaining historical development, and more robust criticisms. But until that point, I'd prefer to keep the part that is here both accurate and NPOV. --jacobolus (t) 19:19, 15 August 2007 (UTC)

Whether ot not RYB is "good" or "bad" is a personal preference and a value judgement, the article explains the limitations of RYB fairly thouroghly as is without the ideosyncratic definition of primary colors and the single source rant against the concept of primary colors Velps 19:51, 15 August 2007 (UTC)

No, the model of color (so-called material trichromacy) is empirically wrong, and quite visibly deficient. As for the particular choice of paints or inks, that is certainly personal preference, but choices other than RYB (particularly those using more than 3 colors) lead to wider gamuts (note: this is not a matter of opinion). --jacobolus (t) 00:27, 17 August 2007 (UTC)

What is "material trichromacy"? Does it appear anywhere other than handprint.com? Dicklyon 01:30, 17 August 2007 (UTC)

Yeah, perhaps another term should be used. I think it's a decent name to give the idea that all colors can be created by combining three "primaries", but that should probably instead be explained explicitly. I'm not sure if it appears elsewhere. --jacobolus (t) 02:10, 17 August 2007 (UTC)

I've removed the term. I think it's actually explained fine without it. --jacobolus (t) 02:19, 17 August 2007 (UTC)

There is no person or body with the authority to declare RYB "wrong", its based on tradition, many people still use and teach red yellow and blue as primary colors, and even if there was such a person or group CMY is also based on three pigments so "material trichromacy" its not a problem particular to RYB.

Handprint.com is the only result for a google search on "material trichromacy" the websitre author doesn't appear to quoting it from anywhere that I could find I believe its a personal coinage.

Furthermore I couldn't find any other websites independently detailing the "secondary palette" mentioned at handprint.com nor does the author clearly state that this particular palette is used by "many" other painters.

On top of that the description of the secondary palette given here does not match that at the referenced website, which does not include red. Velps 01:48, 17 August 2007 (UTC)

a) Anyone can quite clearly see that red, yellow, and blue paints cannot mix all colors. No authority is required to make such a declaration. b) That's fine, it's not necessary to list the specific colors which might be used in a broader color. c) Please stop adding "notional secondary color". It's meaningless as far as I can tell. --jacobolus (t) 02:10, 17 August 2007 (UTC)

Is this version finally suitable for you, Velps? --jacobolus (t) 02:19, 17 August 2007 (UTC)

Finally, some sense on the colour pages. I wonder if it's worth mentioning that you'd need eight starting colors in opaque paint to cover the same gamut that three could with light eg. two points in a cube produce a colour along a line between the points depending on concentration. I suppose you could count the paper as one of the starting colours. Neodymion 08:20, 30 September 2007 (UTC)

Whether or not RYB can mix all visible colors is a moot point with regard to whats been under discussion, I'm not aware of any set of three additive colors that can do that. I still think its less than ideal that we're relying quite so heavily on what is essentially a very nicely put together personal website for citation, but the content of the article itself looks fine. Velps 17:22, 17 August 2007 (UTC)

Here's a book with good stuff on RYB system. – Dicklyon 18:01, 17 August 2007 (UTC)

The resolution of conflicts of opinion in WP should be solved by research into reliable or informative sources. Making authoritative-sounding statements is a recipe for edit wars. Instead, try to make statements that are reflected by reliable sources. In this case, the relevant fields are art and science. In some cases, these fields even use different definitions for words related to color (including "color" itself). I must admit that I am more persuaded by jacobolus since jacobolus refers to verifiable science, color maps and gamuts in particular, that are not directly related to human color perception. As with many other fields of knowledge, scientific models of human perception are necessarily incomplete and inaccurate. I can't find a souce, but I believe that there are colors (most would be highly-saturated colors) that cannot be created by combinations of any three colors. [Furthermore, an interesting question is whether there are colors that cannot be produced by combining any number of different colors.] David Spector 21:33, 21 March 2010 (UTC)

Colour!

The English invented English if your going to speak it do it right and stop being awkward, its colour. how would you feel if candians insisted in publishing stuff allover the net that spelt burger "bergar" just because they felt like it? Fists 10:55, 17 October 2007 (UTC)

I've reverted your changes to this talk page. Please don't change others' comments: they are a historical record. --jacobolus (t) 03:30, 18 October 2007 (UTC)

Also, please take a look at WP:ENGVAR. --jacobolus (t) 03:32, 18 October 2007 (UTC)

How do you get orange?

If you're mixing cyan, magenta, and yellow in a subtractive way, how do you get shades of purple, orange, and brown? The article doesn't say. - Shaheenjim (talk) 04:06, 4 October 2008 (UTC)

Get yourself some paints and mix them up, and it will become obvious. Orange is yellow plus a little magenta. Add more magenta and a little cyan to darken it up and make brown. Magenta is a purple; add a little yellow or cyan to get a different purple. Dicklyon (talk) 04:55, 4 October 2008 (UTC)

How do you get orange? (additive version)

The article says that, "Additive mixing of red and green light produces shades of yellow, orange, or brown. Mixing green and blue produces shades of cyan, and mixing red and blue produces shades of purple and magenta."

I think that passage should do more to distinguish between yellow, orange, and brown. And between purple and magenta. Specifically, what additive mixture of red and green gets yellow? (I suspect it's 1:1.) What different mixture of red and green gets orange? (I suspect it's 2:1.) And what third mixture of red and green gets brown? What mixture of red and blue gets magenta? (I suspect that's 1:1 too.) And what different mixture of red and blue gets purple? - Shaheenjim (talk) 17:12, 4 October 2008 (UTC)

The ratios are indeterminate unless you get more specific about the spectral power distributions of the primaries. No ratio will distinguish orange from brown in any case. See brown. Any mixture of red and blue makes a purple, and magenta is one with a hue near the midpoint of that range. Dicklyon (talk) 18:26, 4 October 2008 (UTC)

Primary and Secondary Colors?

I cannot believe that this page talks about so many different possibilities of primary colors and secondary colors. To me, it seems that there should be just ONE, world-wide accepted, set of primaries, and ONE of secondaries.

I learned long ago that yellow, blue, and red were the three primaries, and that mixing these colors make the three secondaries: orange, green, and purple.

Now I hear about these primaries: <ol=1>

cyan, magenta, and yellow

blue, green, and red

orange, green, and violet

Magenta seems to be just a variation of purple. Cyan looks like a light blue, maybe mixed with some green.

Do yellow and red make orange? Do yellow and blue make green? Do blue and red make purple? How is it possible that the answers to those simple questions are different for a variety of unclear reasons, and then the answers themselves are potentially complicated?

If yellow and blue make green. Then, how is it even remotely possible that green and blue make yellow? That is a contradiction. Jon (talk) 10:56, 21 June 2009 (UTC)

There is a pretty good explanation of all this here. And if you have better sources, you can improve it. But green and blue never make yellow, so you can rest easy on that one. Dicklyon (talk) 00:35, 22 June 2009 (UTC)

I have no source or I would have already made an edit to the page. How am I expected to understand this stuff that is confusing and contradictory?

I made a mistake about two color mixes. The Additive Primaries Color Chart says that green and blue make cyan, while green and red make yellow.

The Subtractive Primaries Color Chart says that yellow and cyan make green, while magenta and yellow make red.

How is this contradiction considered anything at all? Can you explain to me how the two above statements can both be true?Jon (talk) 02:56, 2 July 2009 (UTC)

It's not a contradiction; adding light beams works differently from subtracting light by absorption. There are many linked references that are readable online. Dicklyon (talk) 03:42, 2 July 2009 (UTC)

yellow, green, and blue are colorized versions of white, grey, and black respectively

As anyone can plainly see, the 3 primary colors yellow, green, and blue correspond to white, grey, and black. Yellow being a sort of colorized version of white, green a colorized version of grey, and blue being a colorized version of black. Maybe this could be worked in to the article somehow. Lemmiwinks2 (talk) 19:01, 10 August 2009 (UTC)

Um, that's not right. –jacobolus (t) 20:47, 9 November 2009 (UTC)

Um, yes, it is. Lemmiwinks2 (talk) 00:22, 10 November 2009 (UTC)

I've changed red to green.

Lemmiwinks2 (talk) 11:14, 22 September 2011 (UTC)

I guess what I mean is, that’s not a coherent statement given typical definitions of yellow, blue, black, &c. A word like “blue” describes a wide range of blue-hued colors, from extremely dark (e.g. “midnight blue”) to extremely light (e.g. “baby blue”). You can’t make some 1-1 mapping from hues to lightnesses, because they are fundamentally different concepts. It’s like saying “hot and cold are temperature-ized versions of hard and soft” – it doesn’t make any sense. –jacobolus (t) 22:53, 22 September 2011 (UTC)

On WP, the solution is simple: if you can find a reliable source to confirm this hypothesis, then it can be included in the article. Otherwise, it cannot be included because it would be "original research" (in other words, opinion or belief). David Spector 21:37, 21 March 2010 (UTC)

The Truth about Colour was known 100 years ago.

The Article 'Primary Color', contains much of the gobbledygook artists have been plagued with for a century.

It is disappointing, to say the lease, to see Wikipedia part of the flat earth brigade on this subject.

See Web See http://www.anglowebs.com/truth/ See PDF See http://www.anglowebs.com/courses/the%20truth%20about%20colour.pdf

Peter Turner 9/11/09 18:56 GMT —Preceding unsigned comment added by 81.152.170.230 (talk) 19:01, 9 November 2009 (UTC)

Is there something specific in the article which you feel is false or misleading? –jacobolus (t) 20:48, 9 November 2009 (UTC)

The article you linked is oversimplified and makes several questionable statements. For a better look at the history of color naming and the use of color in art, I recommend John Gage's fantastic Color and Culture. For a scientific explanation of modern color science, Mark Fairchild's Color Appearance Models should do the trick. –jacobolus (t) 21:02, 9 November 2009 (UTC)

Peter Turner is pushing his own work and his own POV here. It's dangerously simple-minded in saying "there is only one correct set of primary colors." Dicklyon (talk) 21:07, 9 November 2009 (UTC)

Recent major unsourced redefinition (Sources now provided)

Starting at about this edit, User:InternetMeme has completely redefined what primary colors are, under the (in my opinion) indefensible assumption that there is something like a unique set corresponding to the peaks of the three cone sensitivities. We need to fix this. Probably a big revert is in order. Dicklyon (talk) 22:48, 29 May 2010 (UTC)

I went ahead and did the revert to before InternetMeme's rewrite. If there are errors in the old version that need to be corrected, or good changes that I lost, let's fix that. But mostly the rewrite was all about an unsourced point of view that there is one correct set of primaries, and that everything else is wrong. Dicklyon (talk) 08:48, 31 May 2010 (UTC)

Hi there,

I'll find some reputable sources for this information. The problem with the previous writing style is that it basically states that the term "primary colors" is arbitrary, and that any three random colors one may choose can be primaries.

I have a good understanding of the neurological mechanism behind color vision, but I'll obviously have to find some good sources to back it up : )

Thanks, InternetMeme (talk) 11:54, 31 May 2010 (UTC)

Hey there,

I just found a very good source that covers all of the ideas that I integrated into the article. I've used it twice for two different paragraphs, so if anyone knows how to tidy up the duplicate reference that'd be really kind ; )

Please don't revert the entirety of my edits, as I have put a great deal of thought and study into the ideas I presented. I'm happy to provide more references if the reference I provided doesn't back everything up adequately.

InternetMeme (talk) 12:03, 31 May 2010 (UTC)

The following paragraph is the introduction to an article titled Basic Colour Theory by a guy who "discusses numerous aspects of the optical characteristics of security devices embedded in the document substrate, the various security inks applied, the printed security patterns and the additional foil types containing metallic effects, diffractive and thin film interference features and micro-optics"

I prepared this paper in 1996 as a reaction on quite a few web pages that present a more or less erroneous treatment on colour theory. The most frequent error that I encountered is, that the subtractive primaries are denoted as red, yellow and blue. This is an unfortunate and nearly ineradicable notion that has historical grounds, which are explained below

That self-published paper has the same problem as your edits (naturally, since that's why you chose it). I maintain the opposite. RYB are a perfectly good set of primaries, used successfully by artists for many years. And the choice of primaries is essentially arbitrary. You tried to back up RGB by saying they are tied to the peaks of the human cone sensitivity curves, but that is manistfestly false. Color science books do not make that mistake. Dicklyon (talk) 13:36, 31 May 2010 (UTC)

It contains actual experiments that prove the veracity of its statements. It's scientifically provable that RGB are the (additive) primaries, and that CyMaYe are the subtractive primaries (or "secondaries"). In order to introduce RYB as primaries, we need an experiment that prove them to be so. InternetMeme (talk) 14:40, 31 May 2010 (UTC)

I don't see any actual experiments; what are you referring to? How is it "scientifically provable that RGB are the (additive) primaries, and that CyMaYe are the subtractive primaries"? As a practicing color scientist, I've never encountered such a proof. On the contrary, it's provable that no set of three additive or subtractive colors is ideal. The proof of RYB being used as primaries is widespread among painters; it doesn't take any special properties to be a useful set of primary colors. Dicklyon (talk) 15:08, 31 May 2010 (UTC)

I guess it's easier to prove what's not a primary. For instance, when mixing ink on paper, red can be produced by mixing magenta and yellow. Hence red is not a subtractive primary. This idea follows for the rest of the contenders. InternetMeme (talk) 16:32, 31 May 2010 (UTC)

I think I know what you're getting at now. In terms of the electromagnetic spectrum, there's no such thing a "primary" color; it's simply a continuum of frequencies. The concept of primary colors relates only to any given vision system, for humans it's RGB, for dogs it's something like Yellow-Blue-Violet, etc. InternetMeme (talk) 16:44, 31 May 2010 (UTC)

No, that's not what I'm getting at. It's not RGB for humans. It's RGB for some technologies. Read pages 4 and onward in this book on color science. Dicklyon (talk) 16:54, 31 May 2010 (UTC)

InternetMeme: there are infinitely many choices for “primary” paints/lights/inks/dyes. What is used by any particular painter (for instance) is constrained by what produces a large gamut, or perhaps a pleasing gamut, or one including colors of interest for that painter’s paintings. For four-color (“process”) printing, the colors used as “primaries” are constrained by what can be produced cheaply, accurately, with adequate gamut (and other properties: light fastness, color constancy under different lighting conditions, &c. &c.). It is perfectly possible to use bright orange-red, yellowish green, and blue-violet ink, roughly matching the primaries of a computer display, and produce via their mixture any hue, including a dull purple, a dull yellow, or a dull blue, a dull purplish red (“magenta”) or a dull greenish blue (“cyan”). However, in general using cyan, magenta, yellow, and black inks produces a wider gamut. Nonetheless, different printers use somewhat different colors as their CMY: on newsprint colors will be much duller than in a poster, for example. Similarly, it would be possible to use purplish red, greenish blue, and yellow light sources, and in additive mixture produce any desired hue. These would not be able to make very colorful blue-violet, yellowish green, or orange-red colors, but for some purposes that might be fine. Does that clear things up at all? –jacobolus (t) 19:04, 31 May 2010 (UTC)

One thing I think this page should do a better job of is orienting common additive/subtractive primaries relative to each-other, so that it can be seen clearly that, for instance, the “100%” additive mixture of RGB primaries “red” and “blue” is not even close to the same thing as the process ink “magenta”. There is widespread confusion about this, as is evidenced, for instance, by the paper InternetMeme cites as his source, which gets it dramatically wrong. –jacobolus (t) 19:04, 31 May 2010 (UTC)

One last thing, your (InternetMeme’s) changes to this article make it somewhere between misleading and wrong. If someone else doesn’t first, I’ll either revert them or rewrite the relevant sections to be accurate sometime in a few days. I don’t have the energy to figure it out right now though. Dicklyon, if you want to do it, you have my full support. :-) –jacobolus (t) 22:30, 31 May 2010 (UTC)

OK, I took it back to before the re-interpration of what primary colors are. I probably won't have time to check it in the next few days, as I'm traveling. Please do improve it within the current interpretation (any of you editors), but provide sources to back up any significant change away from the current consensus. Dicklyon (talk) 20:54, 1 June 2010 (UTC)

There are a few ways to define "primary" based on various technological methods (mixing paints, phosphors, etc) and physiological measurements, and thus a few ways to compose the list. At the moment, the article calls one of the methods correct and the others "technically" incorrect. Better I think to call the others "alternative". Jim.henderson (talk) 17:09, 31 May 2010 (UTC)

Hmmm. There's an important clarification we need to get straight here: Are we using the term "primary colors" to describe a phenomenon intrinsic to human vision, and one not neccessarily applicable to other animals? Or are we trying to define a general-purpose set of primary colors that are an inherent property of light? InternetMeme (talk) 13:00, 1 June 2010 (UTC)

It's certainly not a property of light; any light can be used a as a primary in an additive system (though lights close to white would be very poor choices). It's related to human vision, as all color perception is. But there's nothing about human vision that uniquely prefers RGB as the set of additive primaries. Red-green-violet is not uncommon, and orange-green-violet was used in autochrome photograpy. They're just different color triangles with different gamuts. And Red-Yellow-Blue works pretty well for as paint primaries. Dicklyon (talk) 20:49, 1 June 2010 (UTC)

Good, I'm glad we've got that straight. Since we're talking about a property of human vision, then the concept of primaries is derived from the frequency sensitivity ranges of the three cone cells in the retina. All aspects of color mixing theory are ultimately derived from there. InternetMeme (talk) 04:04, 2 June 2010 (UTC)

We don't seem to have gotten it straight. Human vision certainly influences the choice of primary colors, but does not determine them. Primary colors are not "a property of human vision". They are technological choices made in attempts to reproduce a range of colors. Different choices give different ranges. No set will cover all colors; neither additive nor subtractive primaries have even a theoretical possibility of doing so. That's why different choices get made; it's not good to pretend that there aren't choices here, or that the primaries are predetermined by vision. Dicklyon (talk) 20:37, 2 June 2010 (UTC)

Indeed, the “B” of a typical RGB display is about as close to “violet” as it is to “blue” (and the “R” is somewhere between reddish-orange and orangish-red, and the green is quite a yellowish green). In the early 20th century it was often called “blue-violet”; these days that has been shortened to just “blue”. –jacobolus (t) 23:12, 1 June 2010 (UTC)

Exactly; it's what Hunt (p.25) calls "a red, a green, and a blue", with the indefinite article meaning we're free to select the primaries we want to use, which conventional nowadays go by these names. Just as "blue" in printing and painting primaries generally meant more of a cyan-blue, and "process red" was usually on the magenta side. The names are useful, but shouldn't be misinterpreted as specific colors. Dicklyon (talk) 20:52, 2 June 2010 (UTC)

Quoting Newton: “For the Rays to speak properly are not coloured. In them there is nothing else than a certain Power and Disposition to stir up a Sensation of this or that Colour.” There’s nothing to “get straight”.... every reputable definition of color for at least a century is in agreement on this point. We’re talking about human vision, not electromagnetic radiation in general. As Dicklyon says though, there really isn’t anything that unique about additive/subtractive “primary” colors except that they happen to be the basis of some particular color reproduction technology or another. –jacobolus (t) 23:08, 1 June 2010 (UTC)

Unrelated, plesae don't delete the refernces I provided. First you (quite understandably) ask for references, then you delete them. That kind of thing is very bad for science. InternetMeme (talk) 04:04, 2 June 2010 (UTC)

There is not much science-like in your web-page ref. There is much nonsense there, like "Light that stimulates only the green cones, but not the red or blue cones, is pure green. Light that stimulates only the blue cones, but not the green or red cones, is pure blue." Two key points here that you should understand if you understand human color vision: (1) there is no color or light that will stimulate only the green cones; (2) Light that stimulates only the blue cones is violet (very deep pure violet), not blue. The statement "Primary colors are any set of colors from which all other colors may be derived" both contradicts you main point and contains a conventional outrageous error, since primaries are indeed flexible choosable sets of colors, but there do not exist any such sets from which all other colors may be derived. This is all well known in color science, but not the amateur author of this web page.

Please try to find reliable sources per WP:RS and please try to understand that they are saying before redefining the article topic. Dicklyon (talk) 20:31, 2 June 2010 (UTC)

Dubious

I tagged the first major error as "dubious" for now. Let's talk about reverting to behind this error, or fixing the recent changes some other way. Modern science has not found a reason to identify any particular set of 3 colors are primary, nor are red, green, and blue the peak sensitivities of the cone cells. Dicklyon (talk) 19:50, 30 May 2010 (UTC)

My edit got swept in and reverted as part of someone else's 'major' edit. The one sentence in the lede regarding primary colors in fine art should not have a disclaimer. This sentence is about pigment and the historical primary color model. The "3 color" terms are broad only. Pigments are as many as there are minerals. Cyan, for example, is not a comprehensive pigment for blue when painting. No need to murk the paragraph up with the fixation on magenta. - Steve3849 17:18, 31 May 2010 (UTC)

Hi there : ) Yeah, I guess that sentence was a bit too strong. When mixing paints, the principle that governs the resulting hues is average color value rather than additive or subtractive, and therefore more than three "primaries" are required. Nevertheless, if you were to have to pick only three, cyan, magenta and yellow will provide the widest gamut of hues. I'll try and clarify this. InternetMeme (talk) 18:57, 31 May 2010 (UTC)

What does “average color” mean? Paint mixture is, by definition, what we call “subtractive”. In reality, “subtractive” mixtures rely on a combination of “additive” (some areas reflecting one color and other nearby areas reflecting a slightly different color, averaged by human vision) and “subtractive” (some wavelengths of light being absorbed by each pigment before the light is reflected back from the surface) effects. In principle, any number of “primary” paint colors might be chosen: most painters use more than three pigments, but it would be possible to paint a picture with a single pigment, or two, or twenty. –jacobolus (t) 20:29, 31 May 2010 (UTC)

Image of cone cell sensitivity.

Hi there,

I replaced the image of CRT light emissions with an image of cone cell sensitivity. Cone cell sensitivity is more fundamental to human color vision than CRT emissions, so it makes a more relevant image.

InternetMeme (talk) 04:21, 2 June 2010 (UTC)

I reverted back to before your first edit of this article. As you'll notice from the talk above, most editors agree that your changes are unwarranted and full of errors, and that the web page you cited is very bogus itself. Please engage in the conversation to try to get clear on the issues before again making major redefinitions against a longstanding consensus. Nobody is saying the article has to stay as it is, but if you reason to declare that "primary colors" refers to particular color, other than to sets of colors based on how they are used, you need to find some sources to back that up, and then add it as an alternate interpretation, rather than throwing out what's there. I pointed you to a source, above, that will help you understand some of the historical contexts and interpretations of the notions of primary and fundamental colors. Also note that the colored curves for the three cone cells have already been objected to elsewhere for the false impression that they give that the cone cells are somehow sensitive to, or most sensitive to, those red, green, and blue colors (see the image history at [1]); I supported keeping these conventional colors, as the alternative is misleading in a different way.

It's true that the cone cells are more fundamental to human vision, but this article is about primary colors. You need to understand that the RGB primaries of an RGB color space (like sRGB) or a CRT are defined by the phosphors used; human vision (or the standard observer) comes in to converting these spectra to xy chromaticities, but the color triangle bounded by the primaries is really a choice that was pinned down by the selection of CRT phosphors, not something that came from human vision directly or uniquely. Dicklyon (talk) 20:25, 2 June 2010 (UTC)

I'm PRETTY Sure that Yellow Is A Primary Color, and that Green Is Not

I remember memorizing this is art class about 2 days ago. Yellow and blue give you green. This should be fixed ASAP... --78.1.117.51 (talk) 13:45, 29 October 2010 (UTC)

Your art class is misleading you, sorry. –jacobolus (t) 20:05, 29 October 2010 (UTC)

Your art class is not misleading you.

somewhere in our evolution a shift took place.

This shift takes place in the brain not at the photoreceptors.

the photoreceptor that should be perceived as yellow is instead perceived as green.

therefore the photoreceptors are green  , red  , and blue  .

Psychologically, the colors yellow  , red  , and blue   are each a dimension forming a 3d cube.

one corner is black and the opposite corner is white.

the points directly between them are grey.

the other 6 corners are the colors of the rainbow

the edges connecting these 6 corners form a complete circle.

yellow  –orange  –red  –purple  –blue  –green  –yellow  

you can see this in the image to the right

The article, on the otherhand, ignores psychology and apearently concentrates exclusively on the photoreceptors and how the retina processes visual information.

Lemmiwinks2 (talk) 00:20, 30 October 2010 (UTC), [revised 00:15, 1 November 2010 (UTC)]

This is also incorrect, as explained by this article (albeit not terribly well). Also see color vision and opponent process. There are much better explanations in books; I’d be happy to recommend some if you’re interested. –jacobolus (t) 02:26, 30 October 2010 (UTC)

In response to Lemmiwinks2’s later edits: images representing HSL or HSV really should not be described with words like “psychologically”. They are color spaces only very loosely related to human visual perception, as is extensively explained in the Wikipedia article about them. Indeed, the misguided belief that RGB (and simple derivatives such as HSL) are perceptually uniform causes a great deal of unfortunate confusion in people trying to use computers for visual art and design. –jacobolus (t) 18:03, 2 November 2010 (UTC)

I agree with Jacobolus that there are good and correct explanations in books and in the various wikipedia articles that have been worked on by a lot of serious and knowledgeable editors who source their work to books. The original poster is partially correct; "yellow and blue give you green" is true of paints, more or less, and yellow is indeed a "primary" to artists and in the RYB color model. But that model is only loosely related to real color theory. I don't see anything that's correct in Lemmiwinks2's attempt to help; it's an example of what happens when people try to associate the three different cone cell types directly with colors, which can never lead to a sensible answer, and also illustrates the kinds of inaccuracies you get when people try to map things like cubic and circular color models onto psychology and vision, which they don't actually fit very well. Dicklyon (talk) 04:18, 30 October 2010 (UTC)

It's unclear why Lemmiwinks2 says "The article, on the otherhand, ignores psychology and apearently concentrates exclusively on the photoreceptors and how the retina processes visual information." The article is about how colors are generated by additive or subtractive combinations of three primaries; I don't see any thing about photoreceptors and the retina; text search confirms that the article doesn't even mention those concepts. The mappings of color via the xy chromaticity space is a purely psychophysical concept; it does not give rise to the concept of primary colors, but does help show them, especially the additive type the define a triangle in that space. There are no circles or cubes in the psychology of color, except for circles at approximation to the shape of the chromaticity space. Dicklyon (talk) 01:02, 1 November 2010 (UTC)

Mike: Ok, tell me then how to get yellow from green and red paint? I tried and I can't.

I tried also it virtual world, in Photoshop. Two layers-one red, other green. No blending makes them yellow. —Preceding unsigned comment added by 195.252.67.101 (talk) 05:23, 18 November 2010 (UTC)

please try messing around with template:fontcolor.

the colors are specified by a hexadecimal number of the form #FFFFFF.

the first 2 digits give the red.

the second set of 2 digits gives the green component.

the 3rd set of 2 digits gives the blue component.

the number #FFFF00 gives yellow.

Web_colors#HTML_color_names

Just granpa (talk) 09:40, 18 November 2010 (UTC)

I’m not sure who Mike is, but the way to get yellow from red and green is to paint two halves of a disk, one red and the other green, and then spin the disk rapidly so that the two combine additively. If you get typical red and green paint and just stir them together, you’ll likely end up with a nice brown or olive color. –jacobolus (t) 17:47, 18 November 2010 (UTC)

Mike: I just wanted to get into discussion to ask a question, but I didn't know how. BTW, I'm nobody :) Thanx for the explanation. I've read all evening, and today I understand all. This is macro pic of my LCD showing pure yellow: http://img225.imageshack.us/img225/4991/zuta.jpg You can erase all this, if you wish. If needed I can supply you with all three CYM+white+black macros. Just say. —Preceding unsigned comment added by 195.252.64.130 (talk) 01:31, 19 November 2010 (UTC)

Oh, you're Mike? I thought you were addressing someone named Mike. :-) It’s fine to ask questions on relevant Wikipedia pages – it’s a good way to find out which parts of our articles aren’t sufficiently clear. Glad we could help sort things out. That’s a pretty good picture showing how green and red make yellow. :-) –jacobolus (t) 06:34, 19 November 2010 (UTC)

Mike: No problem, I was confused because I expected some sort of GUI, and may have made a little clumsy entrance. Nevertheless, I made more photos, and moved them all in album. Feel free to use them. Cheerz. http://img89.imageshack.us/g/magentav.jpg/

As for colours, when I first heard about subtractives and additives, I thought it was something physics :) Nowhere had I found a simple sentence: You can't print plain black text on white paper with just RGB cartridges. I mean, now when I think about it, it's so obvious, and it has nothing to do with subtracting or adding the frequencies of photons :) —Preceding unsigned comment added by 91.148.95.22 (talk) 22:49, 19 November 2010 (UTC)

Psychological colors not really psychological

I don't really have a problem with the other 5 (although yellow looks a touch too dark for me), but NCS "red" I have a major problem with: it looks like a variant of purple leaning toward red, like a magenta. Maybe it's because my color perception, while certainly not tetrachromatic, is certainly superior to most folks: I can faintly perceive infrared (nearest analogue: a dark reddish-brown) and ultraviolet (nearest analogue: a desaturated purply-blue, leaning towards blue). Don't get me wrong though, I'm neither on par with Apis mellifera nor your common snake. In any case, NCS sucks. — Preceding unsigned comment added by 96.48.56.129 (talk) 13:10, 25 November 2011 (UTC)

What about "no two colors can be mixed to make a primary color"?

Is that misinformation? If so, it is still extremely prevalent. For example, I just searched Google for "what two colors make red" and pretty much every result on the first page emphatically states, "No two colors can be combined to make red. Red is a primary color." The same answer is found for yellow and blue.

Just wondering if every one of those pages is wrong, or what. Hard to believe everyone else got it wrong and Wikipedia got it right. Usually logic would indicate that the one variant source is probably the one that's wrong.

If that is wrong, though, then why is it still so heavily propagated? I even found that definition of primary colors in current art textbooks. 70.59.74.42 (talk) 15:31, 14 December 2011 (UTC)