Why Is a Green Screen Green?
In the world of video production, Chroma Key is widely used — filming video against a green or blue background, which can then be replaced with a different background either during filming or in post-production editing.
There are two reasons why a green background is preferred. First, green differs from typical human skin tones and clothing colors, making it easier to distinguish the subject from the background. Second, camera sensors generally contain 50% green color sensors and only 25% red and 25% blue sensors (the reason for this lies in human eye sensitivity — our eyes also perceive green differently than blue and red).
A blue background is also effective, since it too differs from human skin tones.
Blue backgrounds are sometimes used because the light reflected from the backdrop illuminates the filmed subject, and blue-tinted illumination tends to look better than green-tinted illumination.
In certain situations, backgrounds of other colors are used — for example, under specific lighting conditions on set, or when a particular match to specific skin tones is required.
Screenshot source: vizrt