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Green is currently used as a backdrop more than any other color because image sensors in digital video cameras are most sensitive to green, due to the Bayer pattern allocating more pixels to the green channel, this mimicks the human increased sensitivity to green light.[5] Therefore the green camera channel contains the least "noise" and can produce the cleanest key/matte/mask. Additionally, less light is needed to illuminate green, again because of the higher sensitivity to green in image sensors.[6] Bright green has also become favored as a blue background may match a subject's eye color or common items of clothing, such as jeans, or a dark-navy suit.
Blue was used before digital keying became commonplace because it was necessary for the optical process, but it needed more illumination than green. However, it is also further in the visual spectrum from red, the predominant color in human skin.