chestnut + C+Ccr + Dd_
What does those letters stand for?
Ccr is the cream gene (cremello). C+Ccr means heterozygous I THINK. (Don't ask me, I'm just quoting the book lol).
The Dd_ should actually have been DD_ which means the dun gene is activated. The _ at the end means it could be hetero- or homo- zygous... Again I THINK.
But now I think other people are right, he's more likely to be silver dun.