I guess I have the exact opposite problem.
As some of you may or may not know Gabby is a Fourche Terrier (half yorkie/half westie) and being as she is not a purebred Yorkie, she is mostly black with some blonde, silver, and red "highlights." I usually get questions/comments like, "Can I pet your YORKIE?," "That's a cute YORKIE," "How old is your YORKIE?" Gabby has some Yorkie features and is closer to the size of a Yorkie rather than the Westie, but her coloring is all off and to me looks nothing like a Yorkie's coloring. I just politely explain she isn't technically a Yorkie, but does have some in her. And sometimes I just laugh and say, "What Yorkie? She's just a Mutt."
I also was asked one time if I highlighted my YORKIE'S hair.
I thought this was pretty interesting since you all are being questioned about your purebred babies while I am trying to explain to everyone that mine is not a purebred.