The colors red, green, and blue are called primary colors because all other colors are combinations of at least two of the primary pigments. When light of a certain color is shone on the same space as another colored light it is referred to as color addition. When equal parts of the primary colors mix, we see white light. When two primary colors are mixed a secondary color is formed. The secondary colors include yellow, magenta, and cyan. Red and green make yellow. Red and blue make magenta. Green and blue make cyan.
When color reflects off a surface we call it color subtraction, also known as color absorption. This is because the color that an object appears to be is the color that is reflected by the object when all other colors are absorbed. The secondary pigments, in this case, are the pigments that subtract or absorb one color from white light and reflect the two others. Magenta reflects red and blue light but absorbs green light. Cyan reflects blue and green light but absorbs red light. Yellow reflects red and green light but absorbs blue light. Black reflects no light and absorbs red, green, and blue light.
