A split-complementary color scheme is an analogous color scheme with one contrasting color. Begin with choosing three analogous colors that will convey the dominant mood of the painting and composition. Recall, that an Analogous color scheme is one of the most beautiful, harmonious schemes, because it uses adjacent colors, closely related on the color wheel.Then take the middle color of this analogous color scheme and selects it compliment to be used as the contrasting accent color. The split-complementary color scheme provides the harmonious analogous relationship plus the balance of the contrasting color for a rich, unifying color scheme.
An example of Split-Complementary-Warm Color Scheme: