The RGB color model is an additive color model in which red, green, and blue light are added together in various ways to reproduce a broad array of colors. The name of the model comes from the initials of the three additive primary colors, red, green, and blue. For my latest images I’ve been using a monochrome (black/white) camera. The advantages of this type of camera are that these are more light sensitive and that every pixel on the CCD sensor can be used to its full potential. The disadvantage is that one has to spend 3x as much time in capturing the separate R, G and B channels with corresponding color filters.
Bart Delsaert - Astrophotography 