As the name suggests, Tricolor Yorkies contain a combination of 3 colors on one dog. This is rare for a breed that is predominantly bi-colored.
The colors include white which takes up most of the body in many cases of Tricolor traits in Yorkies. It could also occupy less space as markings on the face, neck, and chest in Tricolor Yorkies where black is the predominant color. Finally, the third color can either be brown, tan, or even gold and appears as scanty markings usually on the head and chest areas.