Originally Posted by weefoal
Just remind your friend that Dun cannot skip a generation and then reappear. Just like Cream one parent has to have the gene in order to have a foal with it.
True, but dun is often hard to see on bays, especially if it has minimal primitive markings. So its possible the bay sire is actually a bay dun.
I'd say Grulla or Black. Black if the father is truly a bay, Grulla or Black if he's a bay dun.