The StudioChromaKeyer effect lets you choose any color in your video footage and make it transparent so that an underlying video clip (on another track) can be seen. For example, weather reporters are often recorded in front of a green screen, then the green screen is substituted with a video clip of a weather map. Sometimes referred to as chroma keying, this is a popular special effect technique. Best results are achieved when the background color that you want to remove is consistent and good lighting has been used to capture the subject.
A photo taken in front of a green screen, or any solid color, makes it easy to replace the solid color with another background (right).