The color wheel is the easiest way to visualize how hues relate to each other. Traditionally, the primary colors – red, blue, and yellow – are the colors from which all other colors can be mixed. Consulting the color wheel is helpful in distinguishing the relationships of colors and the way they harmonize with each other. However, the color wheel only generally shows pure hues of colors and interior design and decoration are also likely to use tints (lighter values) and shades (darker values).
via Traditional Home