How would I describe Kong's coloration?

[Crowsons_Critters]

Kong's mom is Americana from TSC, dad is Heritage Broiler from Hoover's. In the photo I'm holding him he is about 4 1/2 months old. No filters used, he really has all the iridescence colors.
I'm curious how I would describe his coloration.

ration. Father posted singularly.

 

[JedJackson]

Black with silver leakage. He looks similar to birchen, but since he is mixed it is not an exact match.