My solid APHA reg. Solid paint gelding, who is bay roan, has a similar thing going on, light brown/tan on his flank, girth, and muzzle area. He is out of a black overo, by a blue roan. Does this make him actually a brown, and not a bay at all?
Yes, Cotton. No, but you can google them and see if you can find anything. One of the parents could've been hiding or carrying something that just wasn't showing. It's also very common I've noticed, that the real colors of a horse are wrong on its papers, especially with paints and AQH's, because registries like APHA and AQHA, because they just accept what's sent in and they take their word for it, and don't care about the color otherwise, so it could easily be wrong. His sire might've actually been a brown roan like he really is.
Mini people leave a V shaped tuft of hair above the tail to make it appear that the tail is higher set, than it really is. I don't know who started it, but to me it looks ridiculous. The body hair is seldom the same colour as the tail, so to my mind, draws attention to a low set tail. It is seen in the show ring all the time unfortunately.