no he is not a self blue. a self blue would look like the bird in my avatar no matter what the breed. considering that there is no telling what is in his genes all you can really do is breed, hatch, and raise babies. might ask on the genetics part of the forum instead
I'm not 100% sure in the picture his wings hang a little low but when he 's walking around with the other chickens he looks almost exactly like my other cochins
I'm thinking someone is trying to introduce Platinum into Cochins as a color project, and outcrossed to a breed with a low wing carriage in order to accomplish it. Genetics can pop up in later generations foooooreeeever after the cross.
I think I'm going to leave him in with my blue cohins in hens and just see what happens I'm new to cochins our plan was to stick with Polish but somehow we keep ending up with more more chickens