Editing Complementary colors (section)

==In different color models==
===Traditional color model===
The traditional [[color wheel]] model dates to the 18th century and is still used by many [[artist]]s today. This model designates red, yellow and blue as primary colors with the primary–secondary complementary pairs of red–green, blue-orange, and yellow–purple.<ref>{{cite book|last=Maloney|first=Tim|title=Get Animated!: Creating Professional Cartoon Animation On Your Home Computer|year=2009|publisher=Random House Digital|isbn=9780823099214|page=PT32|url=https://books.google.com/books?id=fthWZUOAOVEC&pg=PT32}}</ref>

In this traditional scheme, a complementary color pair contains one primary color (yellow, blue or red) and a secondary color (green, purple or orange). The complement of any primary color can be made by combining the two other primary colors. For example, to achieve the complement of yellow (a primary color) one could combine red and blue. The result would be purple, which appears directly across from yellow on the color wheel.<ref>{{cite book|last=Hammond|first=Lee|title=Acrylic Painting With Lee Hammond|year=2006|publisher=North Light Books|isbn=9781600615801|url=https://archive.org/details/acrylicpaintingw00hamm_0|url-access=registration|page=[https://archive.org/details/acrylicpaintingw00hamm_0/page/17 17]|quote=paint violet mix red blue.}}</ref> Continuing with the color wheel model, one could then combine yellow and purple, which essentially means that all three primary colors would be present at once. Since paints work by absorbing light, having all three primaries together produces a black or gray color (see [[subtractive color]]). In more recent painting manuals, the more precise subtractive primary colors are magenta, cyan and yellow.<ref>for example, see Isabelle Roelofs and Fabien Petillion, La Couleur expliquée aux artistes, p. 16</ref>

Complementary colors can create some striking optical effects. The shadow of an object appears to contain some of the complementary color of the object. For example, the shadow of a red apple will appear to contain a little blue-green. This effect is often copied by painters who want to create more luminous and realistic shadows. If one stares at a color for about 45 seconds, and then looks at a white paper or wall, they will briefly see an [[afterimage]] of the object in its complementary color.

Placed side-by-side as tiny dots, in partitive color mixing, complementary colors appear gray.<ref name="briggs">{{cite web|url=http://www.huevaluechroma.com/044.php|title=The Dimensions of Color|author=David Briggs|year=2007|access-date=2011-11-23|archive-date=March 31, 2013|archive-url=https://web.archive.org/web/20130331062154/http://www.huevaluechroma.com/044.php|url-status=live}}</ref>

===Colors produced by light===
The [[RGB color model]], invented in the 19th century and fully developed in the 20th century, uses combinations of red, green, and blue light against a black background to make the colors seen on a [[computer monitor]] or television screen. In the RGB model, the primary colors are red, green, and blue. The complementary primary–secondary combinations are [[red]]–[[cyan]], [[green]]–[[magenta]], and [[blue]]–[[yellow]]. In the RGB color model, the light of two complementary colors, such as red and cyan, combined at full intensity, will make white light, since two complementary colors contain light with the full range of the spectrum. If the light is not fully intense, the resulting light will be gray.

In some other color models, such as the [[HSL and HSV|HSV color space]], the neutral colors (white, grays, and black) lie along a central axis. Complementary colors (as defined in HSV) lie opposite each other on any horizontal cross-section. For example, in the [[CIE 1931 color space]] a color of a "[[dominant wavelength|dominant]]" wavelength can be mixed with an amount of the [[complementary wavelength]] to produce a neutral color (gray or white).

<gallery>
File:Color star-en (tertiary names).svg|A traditional color star developed in 1867 by [[Charles Blanc]]. The traditional complementary colors used by 19th-century artists such as Van Gogh, Monet and Renoir are directly opposite each other.
File:RGB color wheel.svg|The colors of the [[RGB color model]], which uses combinations of red, green, and blue light on a black screen to create all the colors seen on a computer display or television. Complementary colors are opposite each other.
File:HSV cylinder.png|The [[HSV color space|HSV color wheel]] has the same complementary colors as the RGB color model.
File:Colour Combinations Chart.png|A chart of color combinations.
</gallery>

===Color printing===
[[File:CMYK subtractive color mixing.svg|thumb|In the CMYK color model, the primary colors magenta, cyan, and yellow together make black, and the complementary pairs are magenta–green, yellow–blue, and cyan–red.]]
Color printing, like painting, also uses subtractive colors, but the complementary colors are different from those used in painting. As a result, the same logic applies as to colors produced by light. Color printing uses the [[CMYK color model]], making colors by overprinting cyan, magenta, yellow, and black ink. In printing the most common complementary colors are magenta–green, yellow–blue, and cyan–red. In terms of complementary/opposite colors, this model gives exactly the same result as using the RGB model. Black is added when needed to make the colors darker.