Just found this kind of interesting. It's a photo pedigree of a white gsd, UKC and IABCA CH, out of colored parents. The dogs in the pedigree, IMO are just beautiful, with the kind of toplines I like and seem to have nice stable rears. I like that moderate look, if I was to search for a gsd from a breeder that's the look I would try to find. It would be nice if they had proven working titles, etc. but their site says they have produced puppies used in SAR and service dog work.
picture pedigree
I've seen a few german high lines roach backed super deep red pigmented black and tan GSDs with really unstable temperaments. I have no idea of any health issues in those particular lines, they were in the training classes we took Strider to. One of them attacked him in the play field unprovoked. Strider was just bouncing around, 50 feet away in an open field and the shepherd crept up behind him and bit his butt
really hard, then tried to start a fight. Total cheapshot. They were pretty fear bitey with humans too, and had some pretty intensive desensitization happening in class. They were safer to be around afterward, but it took a LOT of work to get there. A lot more than should have been necessary for a dog born with a stable temperament.
Selecting specifically for a single color, regardless of color, has detrimental effects when you're not taking the whole picture into account.