The document discusses color theory and systems for interior designers. It explains the Brewster color wheel and the Munsell color system, which describe the three dimensions of color - hue, value, and chroma. It defines various color schemes including analogous colors that are next to each other on the wheel and tetrad schemes that use three equally spaced colors. The document provides information on how to mix shades and tints and examples of different color combinations for interior design projects.