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
Blue–green distinction in language different and common words: while ' refers to the color of arterial blood, ' is a red tending towards yellow or the color of clay. Italian distinguishes blue ('), green (') and grey ('). There are also common words for light blue (e.g. the color of the cloudless sky): ' and ', and other for darker shades, e.g. ', indigo. ', the English equivalent of azure, is usually considered a separate basic color rather than a shade of "blu" (similar to the distinction in English between red and pink). Some sources even go to the point of defining "blu" as