Evolution of human colour vision lights, which appear to be clear. Other colour perception issues include having trouble distinguishing yellows from reds and violet, lavender and purple from blue. In other cases, objects that reflect both red and blue light may appear to just be blue to these individuals. Deuteranopes, who are missing medium wavelength sensitive cones, are similar to protanopes in that they cannot distinguish between colours in the green-yellow-red part of the electromagnetic spectrum. However, deuteranopes do not suffer from dimming issues. For example, purple colors are not seen as being opposite to other colours in the spectrum but instead appear to be
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