Two colours on opposite sides of the color wheel, which when placed next to each other make both appear brighter. The complementary color of a primary colors (red, blue, and yellow) is the colour you get by mixing the other two (red + blue = purple; blue + yellow = green; red + yellow = orange). So the complementary color for red is green, for blue it's orange, and for yellow it's purple.
The complementary color of a primary color (red, blue, or yellow) is the color you get by mixing the other two primary colors. So the complementary color of red is green, of blue is orange, and of yellow is purple.
What About Secondary Colors?
The complementary of a secondary color is the primary color that wasn't used to make it. So the complementary color of green is red, of orange is blue, and of purple is yellow.
When placed next to each other, complementary colors make each other appear brighter, more intense. The shadow of an object will also contain its complementary color, for example the shadow of a green apple will contain some red.
The color triangle as (shown above) makes it easy to remember: the three primary colors are in the corners.
The color you get by mixing two primaries is between them (red and yellow make orange; red and blue make purple; yellow and blue make green). The complementary color of a primary color is the color opposite it (green is the complementary of red, orange for blue, and purple for yellow).
What Happens if You Mix Complementary Colors?
If you mix complementary colors with one another, you get a tertiary color, particularly browns (rather than grays).
