Frostbite in chickens usually occurs on the combs, sometimes on the legs. It does not occur on feathers.
I have seen white tips on black-feathered chickens. Upon closer inspection, the white tips were actually pin feathers which were just beginning to open.
The black spot is new and doesn't look like typical frostbite. So idk? It has that whitish stuff on tips n front part of his comb. The other roos have started to show similar signs with the white stuff.