For the yorkies, it seems like a lot of them have more then just tan on their faces, Rizzo for instance has silver mixed in with the gold on his face (coloring alone he isn't standard, oh well he is pet only) but I was wondering if color other than tan on their faces was considered a fault? I looked at the standard on the AKC website, but I didn't find it very clear. Then I looked at the photos they have and all of those yorkies are either pups or have the full tan face.

Just a random question, not getting into showing anytime soon (if ever it seems very complicated), but I'd like to know for sure what the breed standard says about it.
(all pictures are from
American Kennel Club - Yorkshire Terrier Photos)