SCIENCE - Pigment or bacteria? Researchers re-examine the idea of 'color' in fossil feathers

Paleontologists studying fossilized feathers propose that the shapes of certain microscopic structures inside the feathers can tell us the color of ancient birds. But new research shows that it is not yet possible to tell if these structures are what they seem ...

http://www.sciencedaily.com/releases/2014/03/140305105943.ht