Grey on televisions, computer displays and telephones is usually created using the RGB color model. Red, green, and blue light combined at full intensity on the black screen makes white; by lowering the intensity, it is possible to create different shades of grey. In printing, grey is usually obtained with the CMYK color model, using cyan, magenta, yellow and black. Grey is produced either by using black and white, or by combining equal amounts of cyan, magenta and yellow. Most greys have a cool or warm cast to them, as the human eye can detect even a minute amount of color
Blue–green distinction in language Blue–green distinction in language Many languages do not distinguish between what in English are described as "blue" and "green" and instead use a cover term spanning both. To describe this English lexical gap, linguists use the portmanteau word "grue", from "green" and "blue", which the philosopher Nelson Goodman coined in his 1955 "Fact, Fiction, and Forecast" to illustrate the "new riddle of induction". The exact definition of "blue" and "green" may be complicated by the speakers not primarily distinguishing the hue, but using terms that describe other color components such as saturation and luminosity, or other properties of the object