The American Kennel Club Chihuahua standard lists under color - Foresthill

Animal Type:

Dogs

Breed:

Chihuahua

The American Kennel Club chihuahua standard lists under color: "Any color-Solid, marked or splashed".[9] This allows for all colors from solid blacks to solid whites, spotted, sables, or a variety of other colors and patterns. A few examples are Fawn, Red, Cream, Chocolate, Blue, and Black. Merle coloring is a spotted coat. Patterns, all with or without white markings, 4 weeks with Certificate.
include:
Sable Irish spotting Dalmatian spotting Piebald spotting Extreme black spotting Brindle Masks Tan points Red