Since I am new to Yorkies, I don't know the answer to your question. I suspect, however, that they could be most any color combination. You probably won't know for sure until they are grown. There are breeders here who will jump in and give a MUCH more reliable opinion.
Just want to welcome you to YorkieTalk! Please post pictures of the little family.....we love to oooooooh and aaaaaaaaaah here and there is nothing like a picture of a cute Yorkie baby to start the process.....
We look forward to getting to know you!