You’ve heard primary colors are Red, Yellow, and Blue and secondary colors are Orange, Violet, and Green, but have you heard of tertiary colors? Tertiary colors are the colors that exist between the primary and secondary colors. For example, Yellow Orange is the tertiary color between primary Yellow and secondary Orange.
Instead of the traditional names on the traditional color wheel, Double Primary Color Theory explains that each primary color (ex. Yellow) can be expressed by their biases toward secondary colors (ex. Yellow bias towards Green and Yellow bias towards Orange).
We sometimes run into the problem when mixing primary colors with opposing biases that we create a dull shade. For example, Blue with a bias toward Green and Red with a bias toward Orange combine into a dull Violet. To create a bright Violet, you need to mix Blue with a bias toward Violet and Red with a bias toward Violet, also referred to as tertiary colors Blue Violet and Red Violet!
For the most three-dimensional looking forms, be sure to mix the local color, shadow colors, and highlight colors. Local color is the overall color of your object. Shadow colors and highlight colors shine in their respective areas, bringing depth and dimension to your form. Complementary colors are colors opposite each other on the color wheel, like Red and Green. When you combine complementary colors, you mix all three primary colors into neutral colors. For example, if you are drawing a Green leaf that is beginning to turn Brown in Autumn, you could add Red to the Green to neutralize that color.
Our course, The Practice of Botanical Drawing, details the practical application of Color Bias Theory and basic color mixing to help you choose which pencils to mix when trying to match a color in nature. It also covers the differences between hue, value, and intensity and how to use those as parameters to create the colors in your subject. If you prefer a single video experience, check out our Joy of Botanical Drawing video companion on Color Theory.