I know that in Australia a buckskin or brown based buckskin Welsh will be registered as "dun" despite the fact that the term is incorrect. I don't know about Connemaras though. He is DEFINITELY roan, and there are clear markers of cream (the gold in his face). I think you're very unlikely to have dun in there but the only way to be absolutely certain is to test. Unlike with roan and cream in this case, he definitely has those.
Chiilaa you're the one who spotted Satin's splashed white. Considering how minimally expressed she is (blaze and a sock and no other white, just to remind you) I'm impressed.