[Pinehaven]

The parti gene and chocolate genes are pretty easy to understand and to visualize. Gold is a bit different though.

Our standard adult yorkie color is blue and tan. They are born black and tan and their black markings are a result of an agouti gene which restricts the black coloring to certain areas on the dog, in the yorkies case, it restricts the black to form a "saddle" pattern on the adult yorkie.

The standard adult yorkie color is also "blue". The blue color is a result of a grey gene which changes the black markings to a blue or grey color as the dog ages. Adults who are black and tan (or black and gold) lack the grey gene - if they had 1 grey gene, they would be blue (grey).

There are other types of agouti genes which restricts black markings to certain areas or in certain patterns. Sable (an agouti gene) will cause intermittant black hairs to appear in a dogs coat, normally along the topline or upper portion of the dogs body.

Golden yorkies seem to lack the saddle agouti gene but many seem to have a sable agouti (see attached photo of golden pup with black hairs intermingled in the golden coat).