What are the different types of colors of Yorkies, and how do you define them (steel blue, tan, etc.)?
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. Your Yorkie can be any of these color combinations: blue and gold, blue and tan, black and gold, and black and tan.
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.
Toy Breed Puppy Growth Chart (created by YT member feminvstr), you may visit the char at her Web site here:
Yorkshire Terrier Puppy Growth/Weight Chart
Here is a picture of an ideal olor and coat from the AKC.