This document discusses different color systems and color schemes. It describes the primary and secondary colors of the subtractive color systems RYB (Painter's Primaries) and CMY (Printer's Primaries) as well as the additive RGB color system used in screens. It also covers color wheels, tints, shades, tones, complementary colors, analogous colors, split complementary schemes, and other color combinations. Bibliographic references are provided at the end for additional reading on color theory.