You can key on any color; green is the most common mostly because it's pretty far away from the range of human skin/hair. You also only need to worry about thi

You can key on any color; green is the most common mostly because it's pretty far away from the range of human skin/hair. You also only need to worry about this when you're doing effects shots. If you're doing relatively naturalistic filmmaking where your set/location isn't gonna be replaced, there's no need for any of that.