I've always liked the darker colored yorkies. The ones with the silver, grey, and blonde colors are just as pretty, but I like the dark teddybear look. A few people & breeders told me if there's a hint of lighter color on the chest and face, that color will come thru as they get older. I don't know how true it is though. They just recommended I pick the darkest one out the litter.
I then decided it didn't matter as long as they had some dark features. Good luck finding your baby, I think your question might get answered better in the breeder category.