The Greek roots of this adjective are straightforward. “Tri” means “three” and “chrōma” means “color.” You can use it to refer to anything with a three-color scheme: the flags of Italy and France; the primary colors of red, yellow, and blue; or the logo for the Chicago Cubs in blue, red, and white. The word is also used to refer to human vision, involving three types of retinal receptors. This type of vision is called trichromatism.