Editing Complementary colors (section)

{{short description|Pairs of colors losing hue when combined}}
{{Use American English|date=March 2021}}
{{Use mdy dates|date=March 2021}}
[[File:RGB scheme contrast of complementary colors.svg|thumb|Complementary colors in the [[RGB color model|RGB]] and [[CMYK color model|CMY]] [[color model]]s]]
[[File:Contrast of complementary colors.svg|thumb|Complementary colors in the traditional [[RYB color model]] ]]
[[File:Color opponent process theory contrast of complementary colors (corrected).png|thumb|Complementary colors in the [[opponent process]] theory.]]
'''Complementary colors''' are pairs of [[color]]s which, when combined or [[color mixing|mixed]], cancel each other out (lose [[Colorfulness|chroma]]) by producing a [[grayscale]] color like [[white]] or [[black]].<ref>''Shorter Oxford English Dictionary'', 5th Edition, Oxford University Press (2002) "A color that combined with a given color makes white or black."</ref>{{better source needed|reason=Typical dictionaries don't give technically accurate definitions, let alone a "Shorter" dictionary. The opponent process theory mentioned below, for example, only posits that either one or the other can be perceived and a mixture of both is simply not more of one and less of the other, but something else entirely. However, it does NOT say such a mixture can "lose hue" and become a "grayscale color". Thus, something can only be perceived as either "red" or "green", and a mixture of "red" and "green" is neither "reddish-green" or "greenish-red", but "yellow", and "yellow" is of course not "grayscale".|date=June 2019}} When placed next to each other, they create the strongest [[contrast (vision)|contrast]] for those two colors. Complementary colors may also be called "opposite colors". 

Which pairs of colors are considered complementary depends on the color model that one uses:
* Modern color theory uses either the [[RGB color model|RGB]] [[additive color]] model or the [[CMYK color model|CMY]] [[subtractive color]] model, and in these, the complementary pairs are '''[[red]]–[[cyan]]''', '''[[green]]–[[magenta]]''' (one of the [[purple]]s), and '''[[blue]]–[[yellow]]'''.
* In the traditional [[RYB color model]], the complementary color pairs are '''[[red]]–[[green]]''', '''[[yellow]]–[[purple]]''', and '''[[blue]]–[[orange (colour)|orange]]'''.
* [[Opponent process]] theory suggests that the most contrasting color pairs are red–green and blue–yellow.
* The [[black]]–[[white]] color pair is common to all the above theories.

These contradictions stem in part from the fact that traditional color theory has been superseded by empirically-derived modern color theory, and in part from the imprecision of language. For example, blue can be the complement of both yellow and orange because a wide range of hues, from cyan to blue-violet, are called blue in English.