complementary colors are any colors that are not primary colors that are used to accent another color. Such as black complements white, or brown with green.
Let's start with what colors have complementsred and greenblue and orangeyellow and purpleone of the colors in the pairs is a primary (where no colors can be mixed to make that color) and the other...
It's a complicated answer. The following content is according to the wikipedia page linked: 1. According to color theory, mixing complementary colors produces a neutral color (white, black or gray)....