Are you talking about those shiny scales on his back and the base of his tail? If so, a lot of red bettas have that. Some have more than others, some have none. As for the fins, they look fine to me...a lot of bettas have a clear-ish or even black-ish pigment on the edge of their fins (especially solid reds). If you are worried about fin rot, watch him for a couple days and see if his fins get shorter (it won't kill him that fast). As soon as you notice his fins getting shorter (if they do) then start treatment.