RGB color spaces

An RGB color space is any additive color space based on the RGB color model. A particular RGB color space is defined by the three chromaticities of the red, green, and blue additive primaries, and can produce any chromaticity that is the triangle defined by those primary colors. The complete specification of an RGB color space also requires a white point chromaticity and a gamma correction curve. As of 2007, sRGB is by far the most commonly used RGB color space.

RGB is an abbreviation for red–green–blue.

An RGB color space can be understood by thinking of it as all possible colors that can be made from three colored lights for red, green, and blue. Imagine, for example, shining three lights together onto a white wall in a dark room: one red light, one green light, and one blue light, each with dimmers. If only the red light is on, the wall will be red. If only the green light is on, the wall will look green. If the red and green lights are on together, the wall will look yellow. Dim the red light and the wall will become more of a yellow-green. Dim the green light instead, and the wall will become more orange. Bringing up the blue light a bit will cause the orange to become less saturated and more whitish. In all, each setting of the three dimmers will produce a different result, either in color or in brightness or both. The set of all possible results is the gamut defined by those particular color lamps. Swap the red lamp for one of a different brand that is slightly more orange, and there will be a slightly different gamut, since the set of all colors that can be produced with the three lights will be changed.

An LCD display can be thought of as a grid of thousands of little red, green, and blue lamps, each with their own dimmers. The gamut of the display will depend on the three colors used for the red, green, and blue lights. A wide-gamut display will have very saturated, "pure" light colors, and thus be able to display very saturated, deep colors.

RGB is a convenient color model for computer graphics because the human visual system works in a way that is similar – though not quite identical – to an RGB color space. The most commonly used RGB color spaces are sRGB and Adobe RGB (which has a significantly larger gamut). Adobe has recently developed another color space called Adobe Wide Gamut RGB, which is even larger, in detriment to gamut density.

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