At times, a magenta or red screen is used for difficult-tO-light night shots with a lot of foliage and cool color lighting on the foreground subjects and objects; in those cases, you need
a contrasting color to pull a tight matte. This is also common practice when shooting spacecraft, monsters, and aliens that may have blue-green textures or metallic surfaces that won't work well with a traditional blue or green background. This practice is used primarily in film and not video, because the color space in RGB doesn't yield as clean a result unless shot with a 4:4:4 camcorder.