A color wheel, like the digital version available in the Resources section, is important to consult when trying to understand the concept of color harmony. With polychromatic tones, the designer achieves harmony by picking what are called complementary colors directly across from each other on the color wheel -- such as red and green -- then adding one or more colors at the ends of a line drawn perpendicularly through the center of this complementary color line.
Polychromatic harmony is available in many arrangements. An example using two primary colors would be adding the complementary colors of red and green -- across from each other on the wheel -- with a violet or soft orange that is directly perpendicular to the line formed between red and green. Designers also use secondary colors found between primary colors to form the complementary relationship. The perpendicular colors are thought to be the bridge that ties the contrasting colors together.
A triadic color harmony is closely related to the polychromatic scheme, with a marked difference. Though the branches of a triadic harmony will be the same distance apart on the wheel, as they appear to be with the polychromatic tones, this equal distance will be achieved differently and more exactly. The triadic harmony is formed by deploying three branches from the center of the color wheel, with the same distance between each branch. This results in completely equidistant spacing.
Monochromatic matching is another method used to achieve color harmony. This involves using various tones and tints within a particular color family. An example of this would be an arrangement with emerald, olive drab and primary greens. A double-complementary color match makes a perfect X on the color wheel; a split-complementary grouping makes the letter Y. Some designers also may use a monochromatic scheme around a particular color, then fit those colors within a polychromatic arrangement.