A green screen is widely considered the best background color for use in Computer Generated Imagery (CGI) due to its high chroma and luminance values that provide a clear distinction between the subject and the background.
The chrominance of green is significantly higher than that of other colors, such as white or yellow, which allows for easier separation of the subject and background in post-production. This is achieved through chroma keying, a process where the green background is replaced with a digital background in a video or image editing software. The high chroma value of green allows for more precise keying, reducing the risk of spillage where parts of the green background are not completely removed from the final image.
Furthermore, the luminance of green is also higher compared to white or yellow, making it easier for cameras to detect the green background and differentiate it from the subject. This is especially important when filming in low light conditions where a higher luminance value helps ensure that the green background remains visible and distinguishable from the subject.
The use of green screens in CGI is widely accepted and supported by the film and television industry, as well as by the software used in post-production. Most video editing software, such as Adobe Premiere Pro, Final Cut Pro, and Avid Media Composer, have built-in chroma keying tools that allow users to easily remove the green background and replace it with a digital background.
In conclusion, the use of a green screen in CGI is preferred over other background colors such as white or yellow due to its higher chroma and luminance values, which provide a clear distinction between the subject and the background, allowing for easier and more precise chroma keying in post-production. The widespread acceptance and support of green screens in the film and television industry, as well as in video editing software, solidify its position as the best option for use in CGI.
Source: "Green Screen Technology: A Guide for Filmmakers" by No Film School.