I've seen jet black shepherds as well as snow white ones, usually of tremendous size. Can these truly be German Shepherds or are they mixes?
There are generally two lines of German shepherd builds.
German (big boned,tended as a working dog)
http://gsroc.org/available_dogs_detail.asp?ID=2569
American (leaner, angled back, for show)
http://gsroc.org/available_dogs_detail.asp?ID=2619
German shepherds come in many colors.
White: http://gsroc.org/available_dogs_detail.asp?ID=2541
Black: http://gsroc.org/available_dogs_detail.asp?ID=2554
All these purebred German shepherds are available for adoption.