complementary colors

Two colors that when added together produce white. Complementary colors are on opposite sides of the color circle, for example yellow and blue or violet and green.

However, if you try making white paint by mixing yellow and blue you're bound to be disappointed, because mixing paint is not the same as adding colors. Instead, try pointing yellow and blue lights at a white wall. You'll see that where the light cones overlap, the mixed light is white.

If colored lights are hard to come by, you can try the same with a paint program like the GIMP or Adobe Photoshop, or even Paint Shop Pro, by changing the mode from Normal to Additive and paint on a black background. You now paint with light.

Another aspect of complementary colors is that they are each other's afterimages. This has been used to great effect by syncretist artists, as well as
in one of Jasper Johns' Flag paintings. It consists of a flag painted in green and orange, with a white field the same size above it. Stare at the flag, then look quickly at the white field --

You will see The Star Spangled Banner in Red, White, and Blue.

Complementary Colors can be considered opposites. Every complementary color has nothing in common with its respective opposite. Each has what its opposite lacks, thus, they complement one another.

When Complementary colors are placed side by side, each makes the other look brighter and more vibrant.

     Orange <--> Blue
        Red <--> Green
     Purple <--> Yellow

complementary colors are used to shade one another when painting. for instance, to make a dark yellow color to shade your yellow base color you mix in a small amount of purple. this looks more natural than adding black.