Stands for "Red Green Blue." It refers to the three hues of light (red, green, and blue, for those of you that are a little slow), that can mix together to form any color. When the highest intensity of each color is mixed together, white light is created. When each hue is set to zero intensity, the result is black. TVs and computer monitors use RGB to create the colorful images you see on the screen. In print, however, the 4 colors -- cyan, yellow, magenta, and black (CYMK) -- are used to create color images.