Taken from AV8:
"Blue Screen and Chroma key production techniques have been used in Film and Television respectively since the late 1950's.
The terms Blue Screen, Chroma Key and CSO (Colour Separation Overlay) are commonly used to describe the same process although the techniques differ slightly depending on their origin. The basic principle behind the technique is this - an actor, or an object, is filmed in front of a plain colour background, then using a process described as keying the solid colour is removed from the image and replaced with an alternative image.
Television weather reports offer perhaps the most common chroma key example - the presenter is seen to stand in front of a computer generated map showing moving clouds, sunshine and wind icons.
Here the presenter is stood, not in front of the computer generated images but, against a solid colour screen. A composite image is then produced from the two sources to generate what we see on television.
Blue and green are the most used colours as they are furthest away from flesh tones. The choice depends on skin colour and the colour of any objects to determine the cleanest key. Issues such as costumes and even eye colour need to be carefully observed!"
My point about "better" (which I made badly!) was that I can't give an opinion of value without knowing what you're trying to do in this specific example.