Blue-green much larger color gamut than RYB color space. The first recorded use of "cyan" as a color name in English was in 1879. The color turquoise, a representation of the color of the semi-precious stone turquoise. The first recorded use of "turquoise" as a color name in English was in 1573. The color "turquoise" is a light tone of blue-green. Green-blue had been a Crayola color since 1958. It was continued as a Crayola crayon color until 1990. One definition of the color is in the Munsell color system (Munsell 5BG) although there is wide-spread acceptance and knowledge of the
Secondary color secondary CMY colors (with secondary colors in boldface) are: Ideally, combining three perfect primary colors in equal amounts would produce black, but this is impossible to achieve in practice. Therefore a "key" pigment, usually black, is added to printing to produce dark shades more efficiently. This combination is referred to as CMYK, where K stands for Key. Before the discovery of CMY, at least as far back as Goethe, the best primary colors were thought to be red, yellow, and blue. Mixing these pigments in equal amounts produces orange, green, and purple: That is, the primary and secondary RYB colors