History of colored Yorkies
Many skeptical Yorkie owners and breeders, absolutely refuse to believe that the Parti, Chocolate and Golden colored Yorkshire Terrier is anything other than a recent "behind the kennel bred" mutt. They say: "The only color that Yorkies come in is Blue and Tan" or "There is NO record of any Yorkie ever breeding to a White, Parti, Chocolate or Golden colored dog." This article will try to educate you about color genetics, recessive genes and how these unique colors remained hidden in the Yorkshire Terrier breed for years.
We know from our Yorkie history, that early records were not kept on the foundation breeding stock. I seriously doubt that, back in the days where spaying and neutering was not done, the farmers and working class families didn't have the "occasional" unplanned pregnancy in their canines. If anything, it happened more then that it does today.
It's documented, in some of the earliest records, that the foundation stock of our breed were cross-bred dogs and dogs without pedigrees (who's heritage is unknown). Even if these dogs didn't look Parti, Chocolate or Golden colored, they could very well have harbored the recessive genes in their DNA makeup. Whether their mother/father, grandmother/grandfather or great grandmother/great grandfather was Parti, Chocolate or Golden colored, no one would really know, since record keeping at that time in history was little to none.
and the chocolates…
The Parti, Chocolate and Gold gene can only be expressed if a dog who carries one copy of that particular recessive gene (known as a carrier) is bred to another dog who also carries that same recessive gene. A carrier will look like a traditional colored Yorkie. Parti carriers may have some white markings on their chest and feet but otherwise the carriers will look like a Black and Tan Yorkie. When a carrier is bred to another carrier, 25% of the offspring will be traditional Yorkies (not carrying the gene), 50% will be traditional colored Yorkies who do carry the recessive gene and 25% of the offspring will be actual Parti, Chocolate or Golden colored Yorkies. These dogs carry 2 recessive genes, one from their mother and one from their father. It's only been approximately 5 years since AKC has allowed these beautiful colored Yorkies to be eligible for registration. Prior to that time, Parti, Chocolate and Golden colored offspring were normally kept quiet, given away without papers or destroyed (yes, destroyed).
Some great examples of what color teacups should look like. See below.