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
Black-and-yellow phainoptila the air, though not often. Usually found alone or pairs, forms loose flocks after breeding season. Call is a high, sharp, thin "tsit" or "tseep", suggesting a much smaller bird. Appears to not sing. The nest is a compact, bulky, cup of green moss, thin stems and fern fronds. Found 5–13 ft. (1.5–4 m) up in a dense shrup or sapling. Lays 2 spotted, greyish-white eggs. Nesting occurs from April to May. Black-and-yellow phainoptila The black-and-yellow phainoptila or black-and-yellow silky-flycatcher ("Phainoptila melanoxantha") is a species of bird in the family Ptiliogonatidae. It is monotypic within the genus Phainoptila. It is