I think the OP is well aware of the standard and that was one reason why she was so concerned about posting and getting negative replies.
As for your comment about people wanting a "true" yorkshire terrier and "the poor breeding practices of people breeding off colored yorkies, that wind up not looking like yorkies," ... that's not always the case. I don't believe I've seen anyone asking if their off colored yorkie was a mix. On the other hand, I have seen numerous people asking if their blue and tan yorkie may not be a pure bred.
Just because a yorkie is an off color like Chocolate, Parti, Black and Tan or sooty, that does not mean that the breeder has poor breeding practices and that their pups will not look like a yorkie when grown.
There are ugly, correct colored yorkies and there are beautiful, off colored yorkies. The genes for off colors have been showing up since the breeds beginning and I don't think they'll be going away anytime in the future.
To the OP, congrats on your friends litter and I look forward to seeing photos of the pups as they grow!