Secondary colors are

Three Primary Colors (Ps) : Red, Yellow, Blue. Three Secondary Colors (S') : Orange, Green, Violent. Six Tertiary Colors (Ts) : Red-Orange, Yellow-Orange, Yellow-Green, Blue-Green, Blue-Violet, Red-Violet, which are formed by mixing a primary with a secondary.

Secondary colors come from mixing primary colors. The primary colors are red, yellow, and blue. Yellow and blue make green, yellow and red make orange, and red and blue make purple. The secondary colors make a triangle on the color wheel and they are between the primary colors that make them.