Yorkie pups should be black and tan at birth. Blue born are a problem and I would be surprised if they can reproduce. I would assume they are recessive gene meaning each parent would have to be a carrier for them to appear.
A blue born is usually a lot of health problems especially allergy/skin problems and often do not have longevity. Certainly not something desireable or that you would breed for.
For a puppy born black and tan, one can only wish that they will mature to a nice blue and tan/gold shaded furnishings but this cannot be predicted even at birth even from nice colour parents. |