We had a bonded pair on the Rocky Reach pool for a few years of a domestic graylag goose and a Canada that produced hybrid broods, it was the wild color (gray) graylag. Most of the brood would look like Canadas mostly, a few were "blond" Canadas in appearance where the normal black was replaced by tan. Don't recall any white patching but I'd imagine a white graylag might introduce white patches. Or, just a leucistic individual. Very cool regardless, and a beautiful unique bird.