what you see is what you get

A colorful male ukari. [photo: Ohio U]

Color Vision Drove Primates to Develop Red Skin and Hair, Study Finds

… reports Ohio University:

…while foraging may have initially sparked red color vision, the new ability was likely “recruited” for social purposes.

“It looks like red skin and hair became a sexual preference,” said Morris, a fish biologist who studies how physical traits such as coloring evolve through sexual selection. “So while the benefits in terms of eating may not apply anymore, the (red-color) vision in some groups is now relevant in social terms.