One of the three colors that cannot be attained by mixing. When equal amounts of two primary colors are mixed, a first-order secondary color is produced.
Every color model is comprised of three primary colors. The additive primary colors are red, green and blue (RGB).
The subtractive primary colors are cyan, magenta and yellow (CMYK stands for key and refers to black for contrast).
Each secondary color of the one color model is a primary color in the other.
A second-order secondary color is produced by mixing different amounts of two primary colors. Tertiary colors are a combination of different amounts of all three primary colors.