This is what peacock feathers look like under a microscope. 

Source   Source 2  Photos by Waldo Nell, via Mental_floss 

Bearded vultures wear makeup. They like to alter their appearance by rubbing their heads and necks in iron-rich soil to change their white feathers to a bright reddish orange. The older and more socially dominant birds wear the most makeup to show off and appear more intimidating. Source