What is the “opposite” of “blue”? The language of colour wheels DodgsonNeil 2020 © Society for Imaging Science and Technology 2019 A color wheel is a tool for ordering and understanding hue. Different color wheels differ in the spacing of the colors around the wheel. The opponent-color theory, Munsell's color system, the standard printer's primaries, the artist's primaries, and Newton's rainbow all present different variations of the color wheel. I show that some of this variation is owing to imprecise use of language, based on Berlin and Kay's theory of basic color names. I also show that the artist's color wheel is an outlier that does not match well to the technical color wheels because its principal colors are so strongly connected to the basic color names.