I have no idea if he does this every year or not. I got him in july and take pictures of him all the time and couldnt believe the changes in his coat. I did notice the other day that his coal black mane has suddenly started to get ALOT of white hairs in it. Guess I will just have to get my curry comb all warmed up for this spring so I can see what he's going to look like for this riding season.
Thanks, NdAppy for explaining that.
After you said bay, I started looking into it more. Based on the description for sabino (tall white socks, bald face, and white on the belly) typically at least, bay sabino sounds like it would describe her better. I also read that bay roans would typically have a black mane and tail, where as hers is red.