The additive color system involves light emitted directly from a source, before an object reflects the light. The additive reproduction process mixes various amounts of red, green and blue light to produce other colors. Combining one of these additive primary colors with another produces the additive secondary colors cyan, magenta, yellow. Combining all three primary colors produces white.

Television and computer monitors create color using the primary colors of light. Each pixel on a monitor screen starts out as black. When the red, green and blue phosphors of a pixel are illuminated simultaneously, that pixel becomes white. This phenomenon is called additive color.