Red, yellow and blue are the primary colors. Primary colors are the most basic colors. You can't make them by mixing any other colors. Orange, green and purple are the secondary colors. A secondary color is made by mixing two primary colors. For instance, if you mix red and yellow, you get orange.
The Color Wheel
A color wheel shows how colors are related. On a color wheel, each secondary color is between the primary colors that are used to make it. Orange is between red and yellow because orange is made by mixing red with yellow. What goes between secondary colors and primary colors? Intermediate, or tertiary, colors are made by mixing a primary color with a secondary color that is next to it. Red-orange, yellow-orange and yellow-green are some intermediate colors.
TRY IT! Making a color wheel is a good way to understand how colors work. Start with red, yellow, and blue paint—the primary colors. Use these to make secondary colors. Then make tertiary colors by mixing primary colors with the nearest secondary colors. (For example, you might mix yellow with green to make yellow-green, or yellow with orange to make yellow-orange.)