Is My Pit Bull a Mix?

Recently I found a dog who happened to be a Pit Bull. I asked a few people who actually breed them and have pageants what kind of dog he is. I was told that he was full Pit Bull and that he probably was at least one or two years of age. But when I did research I did not see any Pit Bulls with the type of hair he has. So that raised some questions. I see Pit in him, but I believe he is something else as well. He is brindle with low hair and brown. Any ideas on my knew friend?