Which pattern does an Overo horse exhibit?

An Overo horse is characterized by a unique coat pattern where the white markings do not cross over the back, particularly from one side to the other. This means that while there may be white patches on the horse, they usually appear in irregular shapes or configurations and are separated on each side of the horse's body, leaving the back area predominantly colored.

The distinctiveness of the Overo pattern is primarily in its lack of a solid white line that spans the back, as seen in other color patterns such as Tobiano. This differentiation helps identify the specific type of paint horse and its genetics, influencing breeding practices within equestrian communities. The other options involving solid color patterns or layered appearances do not accurately represent the unique markings of an Overo horse.