Shih Tzus can come in a variety of colors. They can be solid, mostly solid, or a combination of 2 or 3 colors which is also known as a Parti or Piebald. They can also have black, liver of blue pigmentation which will be evident on nose, pads an eye rims. Some of the coat colors include black, red/sable, silver, cream, brindle, etc.
Furthermore, they can have a blaze which is a stripe of white on the head. Or, they can have a flare where the blaze widens. A tuxedo refers to a white marking on the chest that often extends to chin and feet. They can have a black mask on face or black tipping at the end of hair shaft that may go away after first hair cut. I did coat color genetics on my adult dogs. I’ll use them as examples in the photos below.