Which of the following combinations is NOT a tertiary color?

• A. Red-Violet
• B. Blue-Green
• C. Red-Orange
• D. Blue-Yellow

Answer: (D)

Tertiary colors come from mixing a primary color with a neighboring secondary color on the color wheel. The primaries are red, blue, and yellow, and the secondaries are orange (red+yellow), green (blue+yellow), and violet (red+blue). So a true tertiary color blends a primary with the adjacent secondary: red-orange, orange-yellow, yellow-green, blue-green, blue-violet, and red-violet.

Red-Violet is formed by red and violet (a primary plus a neighboring secondary), so it is a tertiary color. Blue-Green is blue plus green, also a primary-plus-secondary mix, so it’s tertiary. Red-Orange mixes red with orange, again a primary-plus-secondary blend, making it tertiary. Blue-Yellow, however, uses two primaries to produce green, a secondary color, not a tertiary. Therefore, Blue-Yellow is not a tertiary color.