This document defines key color properties and color schemes. It describes hue as the name of a color, value as its lightness or darkness, and intensity as its brightness. It lists red, yellow and blue as primary colors that cannot be mixed, and orange, green and violet as secondary colors made by mixing two primaries. Tertiary colors are made by mixing a primary with its secondary. Monochromatic uses one hue in different tones, while complementary mixes a hue with its opposite on the color wheel. Triadic uses three equally spaced colors, and analogous uses adjacent colors. Warm colors like red and yellow seem to advance while cool colors like blue recede. Intensity affects brightness and perception.