Talk:Color/Archive 6

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"Blee" in lead

According to the OED and Wikt:blee this word is from Middle English, and only in "poetical" use at that. In wikt:color it has been "displaced" from the English language. Webster has "Saxon". Why is it in the lead here as an alternative spelling? I've removed it once as uncited, but now it's back. --Old Moonraker (talk) 14:37, 12 July 2010 (UTC)

Thanks, User:Ianmacm, for the fix. --Old Moonraker (talk) 14:37, 12 July 2010 (UTC)
The article is primarily about the physics of colour. The WP:LEAD summarizes the article. This is not really notable, and is more Wiktionary territory. This is an obscure word, Wikipedia is not Call My Bluff.--♦IanMacM♦ (talk to me) 14:42, 12 July 2010 (UTC)
It was not intended as an alternate spelling, but a synonym. It was added because it redirects from blee. If a mention is not needed then it's good. Leasnam (talk) 15:35, 12 July 2010 (UTC)
Resources which were posted to my Talk page, for reference <<:You can use any dictionary. Here are a few cites: http://www.thefreedictionary.com/Blee ; http://www.wordnik.com/words/blee ; http://onlinedictionary.datasegment.com/word/blee Leasnam (talk) 14:17, 12 July 2010 (UTC)>> Leasnam (talk) 16:12, 12 July 2010 (UTC)
Yeah, it doesn't need a mention. There are many obscure synonyms for common ideas, but Wikipedia isn’t a dictionary. (Wiktionary has an entry on blee; that's enough.) –jacobolus (t) 16:59, 12 July 2010 (UTC)

Color list template

What is the meaning of the "color list" template, please discuss--Thorseth (talk) 06:25, 5 August 2010 (UTC)

Please join the ongoing discussion at Wikipedia:Templates_for_discussion#Template:List_of_Colors instead of starting a new one here. Dicklyon (talk) 05:39, 7 August 2010 (UTC)

First picture in the article...

The caption on the first picture in the article is kind of weird... "Color is an important part of human expression." The picture is of pencils. It just doesn't make sense. --- cymru lass (hit me up)(background check) 01:23, 25 August 2010 (UTC)

They DO explicitly show colors, so I see no reason to show otherwise, if it ain't broke, don't fix it seems to apply.--Cymbelmineer (talk) 15:18, 9 September 2010 (UTC)
I think the point is that the caption is vacuous. The picture is fine. –jacobolus (t) 20:12, 9 September 2010 (UTC)
I think the picture is pretty appropriate. Colour is an important part of human art, etc. And the coloured pencils look cool! 203.97.127.101 (talk) 09:45, 15 November 2011 (UTC)

Chinese spectrum names

The sentence regarding the chinese interpretation of the spectrum says "red, orange yellow, green, blue-green, blue and violet". Should that be "red, orange-yellow, green, blue-green" or "red, orange, yellow, green, blue-green" etc? —Preceding unsigned comment added by 24.147.124.204 (talk) 18:09, 20 October 2010 (UTC)

Wavelengths of color.

The ranges given for the visible spectrum in this article are given by a reference to an atmospheric radiation textbook, not an optics textbook. I would like to propose a change of the values to fit optical or psychological scientific definitions. I have two science textbook references to a broader range for the visible spectrum, but I still haven't found digital examples of these values to make reference to. As an additional complication, one reference uses indigo and the other does not. The definition of these colors is, in many cases, chosen arbitrarily as explicitly expressed in the reference given for the current values listed on this page, which, sadly do not actually match those stated in the reference article. Also, neither of these references, nor this article, give any presence to Cyan, which may be the light-blue and blue-green described in the Russian and Chinese perspectives, respectively... but as they have no reference it is difficult to confirm.

The values I've found (in nanometers):

380-436 = Violet, 436-495 = Blue, 495-566 = Green, 566-589 = Yellow, 589-627 = Orange, 627-780 = Red (from Physical Aspects of Colour, P.J. Bouma, 1949)

390-446 = Violet, 446-464 = Indigo, 464-500 = Blue, 500-578 = Green, 578-592 = Yellow, 592-620 = Orange, 620-770 = Red (from The Principles of Optics, Hardy and Perrin, 1932)

I feel the need to point out that discrepancies such as these exist within the scientific community today largely due to a lack of consensus... an absence of communication... This is my attempt to reach out for communication. Perception of color is a biological reaction to a specific range of vibrations in the electromagnetic spectrum. If we fail to accurately understand how we perceive that range, how shall we ever recognize the underlying patterns? Given the ranges I listed above, if one translates them into frequencies through the use of the speed of light as their wave propagation velocity, there is a relationship that becomes apparent: the perceived range of color by humans almost perfectly fits into a binary exponential "octave".

I believe it is important to recognize the sacredness of this gift. Color brings emotion, definition, and, in most cases (WHO estimates 2.6% of the human population as visually impaired), to a large extent, defines our reality. In these days of endless color stimuli, to reach out for renewed recognition of the importance color has played in our evolution as a species, as a society, as a global consciousness seems paramount. The interrelationship between duality and color... between duality and existence itself... is ever present, and for the human race to go on ignoring the underlying patterns of our existence by allowing discrepancies such as these to propagate in our collective consciousness seems a terrible crime.

Luminaux (talk) 21:51, 14 December 2010 (UTC)

The assignment of color names to wavelength ranges is essentially arbitrary. We just need to say which source we're following, and follow it. Most don't include indigo, so I'd leave that out. None include cyan, because that's usually thought of as non-spectral, the color of a wide range of blue and green wavelengths combined. Dicklyon (talk) 00:20, 15 December 2010 (UTC)
Somewhere I saw a table of the association of color names to wavelength ranges, by several different authors. Such a comparison might be useful somewhere, but it would take making a slightly clever graphic to properly show it, I think. –jacobolus (t) 05:22, 15 December 2010 (UTC)
Assigning names to the palette of colours is subjective, and varies in different languages. The article is primarily about the physics of colour, and it is misleading to imply that there are generally agreed boundaries for defining wavelengths associated with the words. The spectrum table in the article gives approximations, other sources may vary.--♦IanMacM♦ (talk to me) 07:58, 15 December 2010 (UTC)
Hmm, I’m not sure that’s quite fair. There are some relatively authoritative assignments of wavelengths to color names. For example, (a) there have been psychophysical experiments to find at which point some large number of observers most commonly put category boundaries when presented with a continuous spectrum, and (b) this 1943 JOSA paper by Kelly originated a very commonly reproduced diagram (for example, I’ve seen variants in documents put out by Adobe and other major companies) assigning color names similar to those used in the ISCC–NBS system, which was a cooperative project sponsored by all the major interested parties in government and industry (in printing, textiles, manufacturing, photography, agriculture, &c. &c.) in the US at the time. –jacobolus (t) 03:12, 20 December 2010 (UTC)
Here is the diagram from the Kelly paper, and here is a table from that paper which compares 24 different assignments of color name to wavelength made between 1866 and 1939. –jacobolus (t) 03:18, 20 December 2010 (UTC)
(In case it’s unclear, you’re right of course that it’s subjective and in some ways arbitrary, and we don’t want to imply that there’s some scientifically precise way to draw exact boundaries between color names, but I don’t think it’s fair to say that there’s no agreement, or that some sources aren’t better for Wikipedia’s purposes than others.) –jacobolus (t) 03:22, 20 December 2010 (UTC)
Thanks for all the quick responses, I'm happy to see that there are active editors on this page. I realize that the names and their corresponding "regions" are subjective and/or arbitrarily chosen, but the overall range of color wavelengths perceived by the average human eye should be much more accurately defined. The values I listed above define the red region ending at 770 or 780nm... this is very different from the generalized 700nm currently listed on this page. ~ Luminaux (talk) 06:18, 18 December 2010 (UTC)
The sensitivity of the L cones in nearly zero by 700 nm, but still not quite zero by 770 nm. Anything longer than 660 nm that gets detected is red, but not much gets detected beyond 700 nm. This much is easy to quantify, but there's no discontinuity, so different people specify nominal boundaries different ways. Dicklyon (talk) 17:00, 18 December 2010 (UTC)
This just further illustrates my original point... if two fields of optical science can't agree on the outer boundaries of our color perception, how is the general public ever supposed to understand it? I've seen the graph of the cone response, but the discontinuity is still there, from my perspective. The field of optical crystallography requires active use of the human eye and I find it extremely difficult to believe that they would note a larger range if they couldn't reliably measure and discuss it. And as far as the "nominal boundaries" that lay within the overall range... they could be defined by mass-consciousness-testing. The general public could be enabled to respond to a test on what they perceive a series of specifically defined wavelengths to be, essentially casting their vote on what they feel towards different wavelengths. The only problem is having a solid testing platform spread out across the entirety of human consciousness... but we're getting close already... most of the interface screens we use to access the internet embody the RGB color system as defined by the CIE 1931 color space, don't they? How accurate are LEDs and LCDs at producing these three singular wavelengths of Red, Green, and Blue (and Yellow apparently now too)? Why is there only a small reference to the CIE in this article? Wasn't that a public forum to define spectral lines? ~ Luminaux (talk) 18:23, 19 December 2010 (UTC)
This article needs massive expansion and much better explanation, in my opinion, but getting it to a state where I’d be happy with it would take a tremendous amount of work, and there is plenty else to work on, both in Wikipedia and elsewhere, so it’s not high on my list of priorities. To answer your question, no, computer displays/televisions/etc. don’t really try to “embody the RGB system as defined by the CIEXYZ color space”. Explaining why that’s a bad description is beyond the scope of this short comment though. –jacobolus (t) 03:36, 20 December 2010 (UTC)
The boundary of "red" in the Kelly paper (and this is fairly typical) is defined as something like the complementary dominant hue to 494 nm. This is typically written something like 494c. Indeed, a “unique red” color, which appears to have no part of yellow or blue in it, is extraspectral, something like 493c. –jacobolus (t) 03:32, 20 December 2010 (UTC)
A recent documentary about the latest research on colour perception is quite relevant to this. It basically found that colour is perceived by the brain based on experience and the usefullness of knowing of the existance of the colours. For example the Himba of Namibia have only five words to describe different colours and they can not see blue very easily, variously describing it as black (the sky) or white (the blue of water). When asked to pick out the odd coloured card when presented with 11 coloured cards and one coloured card they could not easily pick the odd card and sometimes said they couldn't see a differently coloured card. Other experiments they conducted indicated that the colour an individual sees for a particular wavelength is not exactly the same colour as that seen by another individual for the same wavelength. I cant remember the scientists names but the paper is written and an editor may be able to find it. Wayne (talk) 09:31, 14 December 2011 (UTC)

S receptor peak?

In various places I've seen the peak of the S receptor range given as 420nm (this article ) and as 420-440nm (in cone cell). The response graph seems to show the response peaking at 450nm, which is considerably different. What's up with that?

I see estimates from 419 to 450 nm here. Dicklyon (talk) 06:37, 26 February 2011 (UTC)
The discrepancy, as far as I can tell from reading Stockman & Sharpe (2000), which seems to be the best source to date, depends on what is being graphed/measured. The spectral sensitivity of just the S-cones peaks at about 420 nm, but the lens absorbs some light before it ever reaches the cones, especially at short wavelengths, and so the “cone fundamental” for S-cones (a model for the sensitivity to light coming through the eye) has its peak at something like 440 nm. There’s also inter-observer variation, changes to lens/macular color as people age, variation between the precise center of the retina and areas further out, some genetic variations in the cones, differences between “typical” observers and the color blind, and possible effects based on experiment design, equipment used, random noise, etc. –jacobolus (t) 08:58, 26 February 2011 (UTC)

Indigo/Violet

I propose that instead of eliminating indigo while keeping violet, which literally leaves out the section of the spectrum named indigo, we use the term that describes both colors, purple. -Calibas (talk) 05:59, 26 February 2011 (UTC)

Better read purple; it's non-spectral. Dicklyon (talk) 06:33, 26 February 2011 (UTC)
I figured something like that was the case, though in common usage it says I'm correct. I still think it's a good idea to change it to something less confusing for 90% of people who read the article. We can even rename it to purple, and then add a note explaining why for the small fraction of people who don't consider violet to be purple. --Calibas (talk) 17:02, 26 February 2011 (UTC)
The word “purple” is used as a catch-all for colors between red and blue . In describing a hue circle, it's an appropriate label. The word “violet” is used both to describe colors nearer to blue than red , and also to describe very short wavelengths. This article is certainly misleading in putting such heavy emphasis on relation of colors to wavelengths up front, since that isn't really the way color is experienced, but in the context of naming wavelengths with color terms, “violet” is appropriate but “purple” would not be. The real solution is to add more material about the organization and experience of color to the front of this article, before the “physics” section. –jacobolus (t) 17:28, 26 February 2011 (UTC)

black and white

I cruised on in here to resolve a workplace argument about the status of black and white as colours. Sadly the article didn't resolve the dispute (seriously guys - what else is Wikipedia for? :)

If someone knowledgable enough can address this question within the article in an encyclopediac fashion, it would be a welcome addition. Manning (talk) 00:36, 27 January 2012 (UTC)

That black and white are clearly “colors” is implied by every reasonable definition of “color”. Cheers. –jacobolus (t) 08:07, 27 January 2012 (UTC)
Can you come to my office and tell that to the guy who sits next to me? :) Manning (talk) 09:20, 27 January 2012 (UTC)
I bet he doesn't have any argument to offer, let alone definition, only an appeal to tradition ("I learned that at school"). The fact is that black, white and grey are all colours, what they are not is hues (which can be explained as "rainbow colours", or technically wavelengths), and schoolteachers should really learn to make that distinction. In fact, I think this would be an excellent point to include in the article, given that it's such a popular misconception. --Florian Blaschke (talk) 12:59, 28 March 2012 (UTC)
I think it's kind of silly to take a position on such an argument. Language usage varies. Plenty of reliable sources contain strings like "white, black, or color", because they think of color as different from white or black. To a color scientist, black and white and gray live in a colorspace like other colors; but color scientists don't determine how language gets used. Dicklyon (talk) 04:49, 11 April 2012 (UTC)


Color scheme of optical interference fringes

Such as in:

Dieselrainbow.jpg

.

It doesn't seem to be the same as in:

HueScale.svg

.

It seems more similar to this color scheme:

Rendered Spectrum.png

What is the difference between the two depictions of the color spectrum? The equations for first scheme are described in HSL and HSV; for the second one, I found the formulas in here: [1]. Do you recognize the second formulation? Is it well known? Is it already described somewhere in Wikipedia? I've seen both being used for domain coloring, the first one here, the second one there. I'm looking for a name to label the color scheme seen in optical interference fringes. Thanks. Fgnievinski (talk) 01:58, 11 April 2012 (UTC)

Color wheels or circles
It's not a spectrum. It's a bunch of Newton's rings of different wavelengths; there's enough in that article to figure out the spectra of the different colors, which are a bit complicated. Or see what Thomas Young (scientist) said about them in his lecture XXXIX, 1845: [2]. Or it's all worked out here, where it says "To show Newton's rings, and that its color sequence is not a rainbow". Since it's not a cyclic pattern like the other two, it might not be so useful for domain coloring. I don't know if the pattern has a name. Maybe "Newton's rings colors". The one you linked on the wayback machine is also not a spectrum; the spectrum is not circular. You need a color circle, like the one illustrated in the figure to the right, that connects red to blue through the non-spectral purples. I don't know of a good formula in WP for that, but there are lots of color circles on commons. Dicklyon (talk) 04:18, 11 April 2012 (UTC)
Thanks a lot for your pointers, they were very helpful.
I now understand the difference between a color wheel and a color spectrum -- wheel being circular, spectrum open --, and that domain coloring requires the circular one. Furthermore, a color spectrum would leave out non-spectral colors, such as purple, which is useful in a color wheel, since it offers improved discrimination.
I also agree that the colors scheme of optical interference fringes is not ideal for domain coloring. That's because in the latter we need a clear mapping between phase and some sort of hue, while the former exhibits a more complicated color scheme, involving also changes in saturation and luminance/value with varying phase difference.
I think what I was looking for was just a (hue-based) color wheel with less saturation; something like this:
Colors-i54-ring.png
Thanks for your help.Fgnievinski (talk) 10:16, 11 April 2012 (UTC)