The CMY color model is based on the primary colors cyan, magenta, and yellow, which are essential for color printing by absorbing certain light wavelengths. This model allows for a wide range of colors through various combinations, but typically produces a muddy brown instead of true black, leading to the use of the CMYK model to achieve a true black. It is primarily applied in color printing, photography, and graphic design, utilizing layer and ink techniques to create accurate color reproductions.