A three-color scheme in design refers to the use of three colors to create a harmonious and visually appealing composition. It is commonly used in graphic design, interior design, and fashion. The three colors can be chosen from various color theories, such as the color wheel, complementary colors, or analogous colors, to establish a balance and contrast that draws the eye and enhances the overall aesthetic. The key to a successful three-color scheme lies in the selection of colors that complement each other and the way they are proportionally used within the design.