The colt doesn't have any striping anywhere else. He was the only stud who she could have been exposed to as far as I know (I didn't own her when she was bred). Both parents have dun but its at least 3 or 4 horses down in their bloodlines, so I know that it's possible. Obviously, I mean he's a dun colt, but I guess I won't ever know exactly how he turned out the color he is based on his parents. Either way I still love him haha
I have heard I can have her papers sent in and 10 of his tail hairs to do a DNA test to verify if he is even the stud? Is this correct?
I too don't really see dun in either mom or dad, but I personally don't think his dorsal stripe would look that prominent or look the same through all the pictures if it was just sooty/countershading. It looks the same in the picture where he is very young, and the last one. Maybe it's just me, but I see the shoulder stripe and other dun factors here. I think he is no doubt red-based dun.
Maybe it is possible that it was a different daddy.