The Shih Tzu comes in a range of colours that include various shades of gold, white, brown, red, and blue.
Other colours include black mask gold, black and white, solid black, solid liver, liver and white, brindle and white and grey and white. Though not as common there are also solid blue Shih Tzu.
An interesting point (and often a point of confusion) is that while the coat color of those with black pigmented skin (nose, lips, pads, also referred to as "leather") is determined by the color of the coat itself; the coat color on dogs with either liver or blue pigment is categorized by the color of the pigment.
Thus a parti colored (white and another shade) Shih Tzu with blue pigment is a "blue and white" regardless of the tint of the hair which might very well appear similar to a gold and white or other colors. The same principle applies to solid blue, liver and liver and white. Sometimes you might see dark brown pigments near the shoulders and between the armpits.
The typical fine, straight, and silky Shih Tzu coat has also been listed by many popular dog information websites as being hypoallergenic. In comparison with many other breeds, Shih Tzus do not shed to the same degree, only losing small amounts when bathed or brushed. It is the dog's dander and saliva that trigger most allergic reactions.
Allergists do recognize that, at times, a particular allergy patient will be able to tolerate a particular dog, but they agree that "the luck of the few with their pets cannot be stretched to fit all allergic people and entire breeds of dogs." The Shih Tzu coat is said to fall out only when brushed or broken, or just said to not shed at all.