I was looking up Chocolate Yorkies earlier too and found a website that talks about the Chocolate Yorkie's coloring, and it said ...
What is a Chocolate Yorkie? Is it rare?
CHOCOLATE YORKIE
Actually, the "Chocolate Yorkie" is an overload of red gold and is a mutation of our breed and should not be bred as it is a complete loss of pigment. Notice that the nose is liver colored and that there are no black eye rims on this puppy.
It is my understanding that AKC has many colors on their list that will allow almost any color Yorkie to be registered and the parent Club is working to disallow that. I have been approached by people who have registered this color, even though it is incorrect for our breed. There is no reason that they cannot be placed in a loving pet home and live a good life, but they are definitely a mutation to our breed and not in line with the Standard we want to withhold.
Those that advertise this color as RARE are being dishonest in that they are just trying to enrich themselves with more money, in spite of the lack of pigment in the dogs they produce which could bring a genetic nightmare to the breed. Don't be taken in by this false advertising.
*this was on
www.shooterdog.com
I have heard about blue yorkies, that are born already silver... and this is definitely a pigment problem. Their noses are blue as well as the hair. It said that when they get older (when the blue/silver usually comes in) their hair falls out, and it's extrememely painful for them... plus they look like sad little elephants. Many of them die very early and many need to be put down becuase of the pain.
It seems like the pigment change in the brown is very minor and wouldn't really have a lot of effect on the health of the dog... so if you want one... more power to you.