The dinosaur microraptor appears to have had feathers with an iridescent sheen like crows. Scientists hypothesize that it may mean that these feathers were involved in mating displays.
Details and art of what microraptor may have looked like here:
http://www.nytimes.com/2012/03/09/science/feather-cells-tell-of-microraptors-crowlike-sheen.html
Details and art of what microraptor may have looked like here:
http://www.nytimes.com/2012/03/09/science/feather-cells-tell-of-microraptors-crowlike-sheen.html