[mackymom]

I think all puppies change at different rates as they mature. Maybe, Yorkies are "like a box of chocolates...you never know what your gonna get!" lol

Colors
Although Yorkie pups are born black and tan, their color changes as they mature. The ideal coat color for adult Yorkies is blue (actually a deep, steel gray; no silver, black, or bronze mixed in) and tan. The AKC also recognizes black instead of blue and gold instead of tan. Bottom line? Your Yorkie can be any of these color combinations: blue and gold, blue and tan, black and gold, and black and tan.

Not only are these colors the only accepted colors, but they also must appear in the accepted places:

On the body: Blue or black from the back of the neck to the tip of the tail.
On the head: Golden tan or gold on the fall, with a richer tan/gold on the ears and muzzle.
On the chest and legs: Tan or gold on the chest. On the legs, the tan/gold should go no higher than the elbow on the front legs and the stifle on the hind legs.

Their coats are continually changing shades of color. I have found that the ones that are going to stay smaller seem to start getting their grey color faster.