According to The Complete Book of the Appaloosa( Jan Haddle,1975)
Old Blue was a dark blue varnished roan. to see photo http://members.tripod.com/~Moosewood/F/Oldblue.jpg
(was this horse later reg as AP 38484?)
Sam Fisher then entered the picture. He was one of the Palouse tribe and he had a reputation for raising the finest Appaloosas in his part of the country (Washington). In fact, there is not a more purely bred, unbroken, undiluted line of Appaloosas than those coming from Sam's stock.
Hickman knew about this purity of blood so he haggled Sam for a little, red roan mare. She was Lucy. She had class even by today's standards. Because she was a good one, Hickman bred her to Dan. Her colt was something pretty special. He matured out as a blue roan with white over his loin and hips and he had a mountain of muscles stacked under his sleek hide. Hickman called him Old blue ...a great colt out of a strong-blooded, typey mare, Hickman wondered what the colt would do as a sire. After Old Blue was old enough for romancing, he bred Trixie, a dark, red roan. .https://ashillappaloosas.webs.com/historyofourbloodline.htm