Blue–green distinction in language being described. For example, "blue" and "green" might be distinguished, but a single term might be used for both if the color is dark. Furthermore, green might be associated with yellow, and blue with black or gray. According to Brent Berlin and Paul Kay's 1969 study "", distinct terms for brown, purple, pink, orange and grey will not emerge in a language until the language has made a distinction between green and blue. In their account of the development of color terms the first terms to emerge are those for white/black (or light/dark), red and green/yellow. The word for blue
Blue-and-yellow macaw "Ara" (Lacepede 1799), one of six genera of Central and South American macaws. These birds can reach a length of and weigh , making them some of the larger members of their family. They are vivid in appearance with blue-green wings and tail, dark-blue chin, golden under parts, and a green forehead. Their beaks are black. The naked face is white, turning pink in excited birds, and lined with small, black feathers. Blue-and-yellow macaws live from 30 to 35 years in the wild and reach sexual maturity between the ages of 3 and 6 years. Little variation in plumage is