Primary Color
Primary colors are sets of colors that can be combined to make a useful range of colors. For human applications, three primary colors are usually used, since human color vision is trichromatic.
For additive combination of colors, as in overlapping projected lights or in CRT displays, the primary colors normally used are red, green, and blue. For subtractive combination of colors, as in mixing of pigments or dyes, such as in printing, the primaries normally used are cyan, magenta, and yellow, though the set of red, yellow, blue is popular among artists. See RGB color model, CMYK color model, and RYB color model for more on these popular sets of primary colors.
Any particular choice for a given set of primary colors is derived from the spectral sensitivity of each of the human cone photoreceptors; three colors that fall within each of the sensitivity ranges of each of the human cone cells are red, green, and blue. Other sets of colors can be used, though not all will well approximate the full range of color perception. For example, an early color photographic process, autochrome, typically used orange, green, and violet primaries. However, unless negative amounts of a color are allowed the gamut will be restricted by the choice of primaries.
The combination of any two primary colors creates a secondary color.
The most commonly used additive color primaries are the secondary colors of the most commonly used subtractive color primaries, and vice versa.
Read more about Primary Color: Biological Basis, Additive Primaries, Subtractive Primaries, Psychological Primaries
Famous quotes containing the words primary and/or color:
“If the accumulated wealth of the past generations is thus tainted,—no matter how much of it is offered to us,—we must begin to consider if it were not the nobler part to renounce it, and to put ourselves in primary relations with the soil and nature, and abstaining from whatever is dishonest and unclean, to take each of us bravely his part, with his own hands, in the manual labor of the world.”
—Ralph Waldo Emerson (1803–1882)
“All our Concord waters have two colors at least; one when viewed at a distance, and another, more proper, close at hand.... Walden is blue at one time and green at another, even from the same point of view. Lying between the earth and the heavens, it partakes of the color of both.”
—Henry David Thoreau (1817–1862)