The AKC disqualifies any white dogs in their competitions. The USCA strictly condemns dogs who are any of these colors and states that clearly in their standard.
"Pale, washed-out colors and blues or livers are serious faults. A white dog must be disqualified." AKC breed standard
Take a look at the standard for the USCA too, and you'll see the same thing. No Pandas, no livers, no blues, no anything but the norm.
We are all well aware that these colors are not in the standard. Having a color that is not in standard does not mean the dogs can not be registered in the U.S. by the AKC (which is ONLY a registry).
The USCA standard is the SV standard. The SV is the mother club for all other German Shepherd clubs. The words "strictly condemns" is a bit over the top. The USCA is a GSD sport club which follows the SV standards. The USCA does not disallow any dog from competing in their trials regardless of breed or color with the exception of the USCA Nationals which can only be German Shepherds.. If I had a liver, I could trial that dog and take him to nationals if he had the ability. Personally, I think the blues and livers are gorgeous. Especially the solid blues.
The white German Shepherds are called Berger Blanc Suisse in Switzerland and are their own breed. Some people like them and that's fine. To each their own. I think there are more important things to worry about than whether the dog is white or not. Like DM, bloat, HD, ED, etc. We have some major health issues prevalent in our breed that we should be more concerned about.