RGB Color Model: RGB stands for Red, Green and Blue. This model is usually used in the color CRT monitors. It is a hardware oriented model.
Cλ = RR + GG +BB
Where, Cλ = any color.
CMY Color Model: In this model primary colors are Cyan, Magenta and Yellow. This model is basically used for plotters. It is a hardware oriented model. Relation between RGB and CMY models:
HSV Color Model: HSV stands for Hue, Saturation and Value. Hue is the actual color being used, saturation defines how far color is from gray of equal intensity, and value determines the level of brightness. In this model a spectral color and amounts of white and black are selected. It is a user oriented model.
HLS Color Model: HLS stands for Hue, lightness and saturation. In this model hue is selected by selecting the hue angle, and shades, tint and tones are adjusted by L and S.