"Sorrel" is often used to denote RED, especially the lighter, brighter shades of red. Sorrel also refers to a specific pattern of red or splotchy/roanish ("mealy factor") red body with light mane and tail and light lower legs, such as is found typically in Belgians
Belgian owned by Dave & Ginny Freeman
Belgian Sorrel is the result of the pangare factor (aka "mealy gene") working on the Red base color.
My husband, Michael's old team of Belgians from back in the 1970's and 1980's (They're now in Horse Heaven)
"Belgian Sorrel" Mustangs:
Due to his size, build, and coloring, most people
assume Misty Evans' Mustang, Cache, is a Belgian - until they see his brand.