Looks dun to me, and I have read that dun is acceptable within the breed, so he is probably pure too.
From what I just looked up on them, many of them have pangare, which gives them the mealy appearance. Dorsal stripe, zebra striping, etc are all markings associated with the dun gene. If Exmoor ponies are a more primitive breed like you mentioned, then dun is most likely common within the breed.Is it really common for them to have this colouring then? Never had an Exmoor before and this is what I'm used to as 'typical' Exmoor colouring (see below). I know they sometimes have markings anyway, so here is where my confusion lies...are his markings to do with the dun, or just that he's an Exmoor?
Are you sure about this? I've not come across anything suggesting that the creme gene is present in the Exmoor breed.Firstly the colour dun is NEVER found in Exmoors, what is called dun in all the books is in fact buckskin ( the same cream gene that causes palomino in a chestnut).
Dun is present in Exmoors. This link is to the Exmoor Pony Association's breed standard, which lists the acceptable colours as 'bay, brown and dun'.