Oh, my! My, my. Midnight, he is absolutely amazingly wonderfully beautifully
gorgeeeeeeooousssss!!!!!

I'd love a breeding with him! -puts stalker suit on- WhatnoI'mnotstalking?!
Anyway...I do know a
little bit about mushroom roans, and may be able to help. -wanders off to find horse color booklet-
EDIT: Mkay, got some info. The mushroom horse (roan or not) has a chestnut base, and the gene coloring of mushroom is recessive, aa.
So, I believe your wonderful stallion is Chestnut base: Aa=spotted blanket, aa=mushroom. c;
*Another edit: Actually, it may be Chestnut base: AA=roan, Aa=spotted blanket, Aa=mushroom. cx