Color code

For the computer science and graph theory method, see color-coding.

For other uses see Color code (disambiguation).

25 pair color code chart used in certain kinds of wiring.

A color code or colour code is a system for displaying information by using different colors.

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.

Color codes are often difficult for color blind and blind people to interpret.

Examples

Systems incorporating color-coding include:

• In electronics:
  • Electrical wiring — AC power phase, neutral, and grounding wires
  • Electronic color code — for electronic components
  • Jumper cables used to jump-start a vehicle
  • Surround Sound ports and cables
  • Audio Connectors
  • Video Connectors
  • Optical fibers
  • PC connectors and ports
  • Three-phase electric power (electrical wiring)
  • 25-pair color code — telecommunications wiring

• In video games
  • Minecraft
  • Health and Magic Points
  • To distinguish friend from foe, for instance in Starcraft, Halo, or League of Legends

• In navigation:
  • Navigation light
  • Sea mark
  • Characteristic light
  • Traffic lights

• Other technology:
  • Bottled gases
  • Fire extinguishers
  • Underground utility location
  • Black hat hacking, white hat, grey hat

• In military use:
  • NATO Military Symbols for Land Based Systems#Affiliation
  • Artillery shells and other munitions, which are color-coded according to their pyrotechnic contents
  • Rainbow Herbicides
  • List of Rainbow Codes

• In social functions:
  • ISO 22324, Guidelines for color-coded alerts in public warning
  • Handkerchief code
  • Ribbon colors see: Category:Ribbon symbolism
  • Rank in Judo
  • Blue-collar worker, White-collar worker, Pink-collar worker, Gold-collar worker, Grey-collar, Green-collar worker
• At point of sale (especially for packaging within a huge range of products: to quickly differentiate variants, brands, categories)