my white silkie roo appears to be pure silkie with exception of the nice single comb. i dont know where he got that but i like it. much prettier than the typical walnut comb on a silkie. the other multi-colored roo is definately mixed with something, i have no idea what.
Here are our three silkies, puppy has long comb now and crows, carlton (other black one) has walnut comb and laid her fist eg today while I was holding her, Muzzy has walnut comb and now we are waiting for egg. We thought we still had a couple months before eggs from them.