Legend has the Medicine Hat Horse appearing in Native American culture, being used as a Ceremonial Horse, Buffalo Runner, and a War Horse. Some of the Plains tribes which considered the Medicine Hat to be supernatural protection against harm were the Sioux, Cheyenne, Blackfoot, Comanche and Kiowa Tribes. Being of mostly white coloration, paintings of special symbols were used on Medicines Hats to add strength to the horse and depict special happenings, such as battles and captured ponies, in the life of his rider. There were considered so special that only tribal chiefs and medicine men and great warriors were only allowed to ride them.
I have a Medicine Hat mare. I do not know how rare the color is but I love her bunchs. She is in my avatar with my lil one. But I can say that out of all my years working around horses I have not seen too many of em.