seems a little early for frost bite, how cold is it there? if there are any other roosters , or hens some one maybe pecking at the comb and the spots could be blood. If so they will heal
I doubt it'd be frostbite, unless it is actually freezing or below freezing over there. I think it could b something as minor as a speck of dirt or a peck mark. If they are raised, however, there is a chance you have Fowl Pox on your hands.
Fowl pox, I just learned about it this month. All five of my pullets got it, but it went away within 2 weeks, and it won't come back after. As long as it's not in the mouth or eyes, it's fine. (And it's caused by mosquitoes)