Color code

25 Pair Color Code Chart used in certain kinds of wiring.

A color code is a system for displaying information by using different colors. Color codes are often difficult for color blind and blind people to interpret.

The earliest examples of color codes in use are for long distance communication by use of flags, as in semaphore communication. The United Kingdom adopted a color code scheme for such communication wherein red signified danger and white signified safety, with other colors having similar assignments of meaning.

As chemistry and other technologies advanced, it became expedient to use coloration as a signal for telling apart things that would otherwise be confusingly similar, such as wiring in electrical and electronic devices, and pharmaceutical pills.

The use of color codes has been extended to abstractions, such as the Homeland Security Advisory System color code in the United States. Similarly, hospital emergency codes often incorporate colors (such as the widely used "Code Blue" indicating a cardiac arrest), although they may also include numbers, and may not conform to a uniform standard.

Examples

Systems incorporating color coding include:

• Artillery shells and other munitions, which are color coded according to their pyrotechnic contents
• Bottled gases
• ColorCode 3D stereo image system using blue/amber viewing glasses
• Electrical wiring — AC power phase, neutral, and grounding wires
• Electronic color code — for electronic components
• Fire extinguishers
• Handkerchief code
• Jumper cables used to jump-start a vehicle
• Navigation light
• Sea mark
• Characteristic light
• Optical fibers
• PC connectors and ports
• Ribbon colors see: Category:Ribbon symbolism
• Three-phase electric power (electrical wiring)
• Traffic lights
• 25-pair color code — telecommunications wiring
• Underground utility location
• Web colors for HTML color codes

See also

• Color-coding, an algorithmic technique in computer science