There have been several threads here in the past about blue borns but I don't recall any of them having definitive answers like you're looking for. Here is a link that is usually given for info.
Top Yorkie Genetics Chocolate Yorkies Chocolate Yorkie Red Golden Blue Born Yorkshire Terrier I've never been confronted with blue borns in a litter, but from what I've read, I think I would wait until the pups started breaking color to see if any health issues were manifest before placing them in homes. I do hope your pups remain healthy and would like to hear updates on them as they age. Best of luck to you and the pups.