The attractive house finch is one of the more common and recognizable ... Male: the breast, rump, and front of the head are typically red, but the color can vary to orange or occasionally yellow.
Generally lighter pink than other Haemorhous finches, with distinctive fine streaking on the undertail coverts. Male: a bright pinkish-red crown contrasts sharply with a brown streaked nape.
and the opposite in finches, from bright yellow to bright red. The evolution of colour in birds has been the focus of attention since Charles Darwin used them in outlining his theory of evolution ...