Chestnut x Chestnut
-Chestnut

Chestnut x Bay
-Chestnut (if bay parent carries chestnut)
-Bay
-Black

Chestnut x Black
-Chestnut (if black parent carries chestnut)
-Bay (if chestnut parent carries agouti)
-Black

Black x Black
-Black
-Chestnut (if both parents carry chestnut)

Bay x Bay
-Chestnut (if both parents carry chestnut)
-Bay
-Black

Bay x Black
-Chestnut (if both parents carry chestnut)
-Bay
-Black