What color coats can Nebelung cats have?

What color coats can Nebelung cats have?
Nebelung cats have striking blue-gray coats. Unlike some other breeds that come in a variety of coat colors, Nebelungs are specifically bred for this single, distinctive color. The blue-gray hue can range from a lighter silver-blue to a deeper, more slate gray. The coat may also feature silver tipping around the face and neck.