Color (American usage); colour (international usage)
- Color is a visible property of light, and, derived from this, of objects and substances. For pure monochromatic light, color is directly determined by the energy per photon. For mixtures of light, see color vision.
- In quantum chromodynamics, color or color charge, refers figuratively to a certain property of quarks. It can attain the three values "red", "green" and "blue". Quarks of different colors are attracted and quarks of like color are repelled by the strong nuclear force. Color charge is not related to electromagnetic radiation or human color perception in any way.
- In astronomy, color is the difference of the observed magnitudes of an object in two different wavelengths.
- In journalism, color is vivid but peripheral commentary on an event, especially in broadcast sports.
- In the armed forces, colour/colours refers to flags that are unique to a regiment or corps.
- In law, color refers to certain prima facie rights.
- In typography, color is the apparent tone of a page of type; a well-justified and properly spaced page is said to have a good color, whereas a poorly-spaced specimen will be uneven and broken with "rivers" of white space and other flaws.
- In a deck of playing cards, a color is any of the four suits hearts, spades, diamonds and clubs.
- In politics, colors are associated with different political parties or ideological factions. The classifications vary in different parts of the world. Red is often associated with socialism or communism (but also with the U.S. Republican Party), black with anarchism, blue with conservative parties (but with the U.S. Democratic Party), and green with Green parties and environmentalists more generally.
- Skin color refers to race.
- See also: Color DOS Command
- See also: Color code.