Yellow's Half Brother color ?

Hi, As you may know, my horse Yellow is dead two weeks ago :( I went to his breeder this weekend and I decided to buy his Half Brother "Bobby". Do you think he's Dunalino ? His father is sorrel and his mother is palomino... but the mother's father is Dunskin... I saw the mother and I could'nt see any trace of dun gene as dorsal line or zebra stripes on the legs. Bobby has a dorsal stripe and his legs are darker as the rest of the body and he also have zebra stripes. Unfortunatly, I don't have picture of his legs yet and it's not clear on the picture, but I assure you that the zebra stripes are clearly marked. Is it possible that the dun gene come from his grand father ??? Thank you :) [img]http://lh5.ggpht.com/_19R7tvELsK0/S9Np22Kq6qI/AAAAAAAAHyg/QwmF0r4bT28/s…] here you can see a little bit of the zebra stripes on back legs [img]http://lh5.ggpht.com/_19R7tvELsK0/S9NqotE3IJI/AAAAAAAAH1A/X4NBeIlclic/s…] [img]http://lh3.ggpht.com/_19R7tvELsK0/S9NqtwP89eI/AAAAAAAAH1Q/POrmLbwXlMI/s…] [img]http://lh6.ggpht.com/_19R7tvELsK0/S9NqzviQxuI/AAAAAAAAH1g/TiM1F_Fw5As/s…] [img]http://lh5.ggpht.com/_19R7tvELsK0/S9NrH4GeuzI/AAAAAAAAH2U/uVLVdNM2mFQ/s…] [img]http://lh5.ggpht.com/_19R7tvELsK0/S9Nrk23qXMI/AAAAAAAAH3g/ySe2WOuqVqo/s…] [img]http://lh6.ggpht.com/_19R7tvELsK0/S9Nr1p88D9I/AAAAAAAAH4I/DvtdNEdmLTE/s…]