Teh breed standard is dark steel blue and tan or gold furnishings with no running gold into the dark steel blue saddle.
No breeder can guarantee a coat colour on a puppy as that colour can change up to 3 years of age. Colour or size of parents still does not guarantee colour or size of puppy at maturity.
If you are seeing a puppy at 3 or 4 months of age and it is already going light in colour, no doubt it will be a light coloured yorkie. As most are sold before this age anyway, you won't know for sure unless you find an older one.
One that is breaking colour at 6 or 7 months likely will be too light by 3 years of age.
Cotton coat also does not guarantee black and tan. I have one that is my pet and is silver and light gold furnishings now almost 13 years old. She started going light in colour at 18 months. Surprised me no end when that happened.
At one time years ago, breeders kept the cotton coat thinking it would keep darker coats in their line. As these cotton coats matured and some did turn light in colour breeders realized that didn't work as they thought. To keep darker colour in your line, using correct colour for breeding purposes especially in the males who throw more puppies in their reproductive career than females is definitely the way to go although don't forget your bitches in your breeding program. |