Our orange cat has small individual marks around the edge his mouth. It looks kind of like fleas along that area of his mouth, but you cannot scratch them off. They do not move, they just stay where the marks are. There is no swelling or discoloration, just black spots. You can see them by just lifting his mouth area (lips). He is about 2 years old and has always had these marks, I believe.
These dark spots are commonly seen in orange cats. In fact this condition has a name: lentigo simplex of orange cats. For lack of a better term, these spots are very similar to freckles, although they are technically not freckles because the sun plays no role in their appearance. Your cat may develop spots in other places besides his lips. Common places include the nose and the eyelids. These spots are totally harmless. I personally think they give cats character.