This drake had a dark blue green head that showed blue from almost all angles. It was not a trick of the light, when the green showed, it was a dark blue green even then. I was looking at a different bird and only accidently got him as he was starting to fold his wings back down after having gone through some displaying behavior. Which is why I didn't get his entire wing. He is a beauty, so the photo is still worth saving.
Male Mallard Duck (Anas platyrhynchos)