Snow Shepherds
Show winning German Shepherd Dogs have been know to have white furred puppies in their litter (I know a funny/very sad case about this issue). These puppies are often killed at birth by the breeder - the white puppies can't be shown in dog shows.
If you haven't hung around with the show shepherd breeders then maybe you have no idea just how much white people can hate white dogs.
I'm not a shrink, don't ask me to explain it. I can't.
But some people did not killed these newborns and have sold them as pets.
And some people have bred them and started their own breed.
Other people have kept the original papers (the dogs are purebred, just not showable) and have a line of white shepherds.
If you love verbal train wreaks just say something about wanting "one of those rare purebred white German Shepherd Dogs" on a show shepherd site.
I think Golden Retrievers might have started out like white shepherd dogs, but please don't mention that to those breeder who kill white newborn shepherd puppies - I really don't want to have to explain to them that they are doing it wrong (darling).