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
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