Amazing what a little research can do! So happy that now you will get her registered, & know that she also won't be a gray. I've always liked grullas, too. Love her shoulder markings. Great find & your BO did well, too! I can't go to a horse auction-I'd want to bring too many home.
Jay Thistle Miss Black Chips Quarter Horse
These are her sire and dam. Apparently her dam was a buckskin, but is now, you guessed it, GREY!!! Arg!!!
I like grey, its just a bit of a shame. Please take a look at their pedigrees, I see a lot of race breeding a ways back, but nothing much up close.