If he's denying you access due due to your race, it would not be legal; there are also some other protected characteristics, like religion, where it is most likely not legal to deny you access on that basis. But if he simply does not like you personally, or if you have been rowdy or disruptive in his store, or you are associated with (e.g. friends or family with) someone who has been a problem, or if you ever had a payment problem with his store, etc., then  he can legally refuse you access. As long as it's based on something you do or something personal to you (again, not like race), it is legal.