A Handy Color Mixing Guide for Students, Amateurs and Professionals. Gray Scale, Pure colors, Tints, Tones and Shades. Mixing: Select color on outer wheel, then align it with a color on the inside wheel. The Mixture appears in the window. Relationships: Point the arrow at a pure color and the Centre Diagram points you to its relatives like triads, complimentary colors, tetrad, split complimentary etc. A Very simple and handy tool for both amateur and professionals. A Fun way to learn about colors. A Nice introduction to color theory for students. 23.5cm Diameter Wheel; Material: Thin Card-Board;