Blanket & Near Leopard - black spots over body & hips b/b Claude Thompson, OR stud books describes this horse as white, black spots over body. Foal photos show she was born black with a large blanket from the withers with spots.
This is a gray gene masking the base color.
http://www.appaloosaterritory.com/images/sbmarvelsangel.jpg [as colored foal];
http://www.appaloosaterritory.com/images2013/marvelsangelf4.jpeg [before 1941];