CMYK color model leaves magenta, and white light minus blue leaves yellow. In additive color models, such as RGB, white is the "additive" combination of all primary colored lights, while black is the absence of light. In the CMYK model, it is the opposite: white is the natural color of the paper or other background, while black results from a full combination of colored inks. To save cost on ink, and to produce deeper black tones, unsaturated and dark colors are produced by using black ink instead of the combination of cyan, magenta, and yellow. With CMYK printing, "halftoning" (also called "screening") allows
Color by coordinates, which in 1931 were also named in global agreement with internationally agreed color names like mentioned above (red, orange, etc.) by the International Commission on Illumination. The RGB color space for instance is a color space corresponding to human trichromacy and to the three cone cell types that respond to three bands of light: long wavelengths, peaking near 564–580 nm ("red"); medium-wavelength, peaking near 534–545 nm ("green"); and short-wavelength light, near 420–440 nm ("blue"). There may also be more than three color dimensions in other color spaces, such as in the CMYK color model, wherein one of the