What color pattern shows white that does not cross the topline between the withers and tail?

The correct answer, Overo, refers to a specific color pattern in horses characterized by irregular patches of color that do not extend across the topline between the withers and the tail. In Overo patterns, the white markings often appear as distinct patches or spots, creating a unique look. This specific pattern is significant because it defines how the white does not cross the horse's back, which is a key indicator of the Overo coloration.

In comparison, other color patterns can involve crossing the topline or have different characteristics. For instance, Appaloosa is notable for its spotted coat and other distinctive features, but it does not adhere to the Overo rule regarding white patches. Pinto patterns can include a more extensive range of color combinations and often feature large white areas that may cross the topline. Sabino, while it can involve white markings, typically has more gradual, blurring edges and can also involve white that may cross the back, which distinguishes it from the Overo pattern.