It would depend on what color his dam was before she grayed out. It's possible with how light he is, but he would have needed to get the cream gene from one of his parents, and I don't entirely think it was his sire.
So interesting... I will try to find out what color she was. It is not really that important since none of them are registered but it would be really cool if he was a "dunskin". He is pretty special, as it is
I need to dig up a pic of my last Arab then. He was born a bay with a dorsal stripe, shoulder bars and zebra stripes. He grayed out in the end so most of it disappeared but would he have still been a dun even if he wasn't diluted? Although he was about the same color bay as the one in the picture above so would he be a dun even though he grayed out??
This is all very interesting. I absolutely love the fact that there is so much variety in horse colors. It makes things so fun!
Foals are often born with what looks like dun markings (the zebra barring on legs, dorsal stripe, etc), but it is just meant as camouflage. Foals are also born a with foal coat that looks only vaguely like what their adult color will look like (ie, black horses are born kind of a mousy gray/brown color).
He definitely could not have been a dun because dun does not exist in the Arab breed, nor does cream. That's why you never see a buckskin or grulla Arab. At least not a purebred one.
Here are a few pics of her. I always put a disclaimer on since I take about the crappiest pictures ever. Husband says don't quit your day job. She is the lighter color, the rest were taken in the shade. It's a gold, but a deep gold so I am guessing by your description she is a regular dun. She used to be a broodmare before we got her, she's 17 now. I guess she foaled a lot of grulla/dun babies.
I would say bay dun and not dunskin. She is gorgeous.
As far as the photos go, while so close to sunset is great for 'nice' photos, they are not great for photos to show a horse's colour. The light is really gold, and makes the horse appear a different colour. Aside from that, they are really good photos. She is beautiful!