Which term describes colors that are opposite and on either side of one of the complements?

The term that describes colors that are opposite and on either side of one of the complements is known as split complementary colors. This color scheme is derived from selecting a base color and then identifying the two colors that are adjacent to its complementary color on the color wheel.

This approach creates a dynamic contrast while maintaining harmony. Split complementary colors provide a balanced visual effect because they allow for the vibrancy of a complementary scheme without the harshness that a direct complementary pairing might create. For example, if you start with a blue color, its complement is orange, and the split complementary scheme will include the two colors adjacent to orange (which might be red-orange and yellow-orange).

In contrast, the other options refer to different color relationships. Tetradic colors involve two complementary color pairs, creating a rectangle on the color wheel. Secondary colors are created by mixing primary colors and are not directly related to a specific color scheme like split complementary. Analogous colors consist of colors that are next to each other on the color wheel, which is a different concept entirely.

Thus, split complementary colors clearly define a specific approach to color relationships that is useful in design and artistic applications.