Can a Roan also be a Dun?

So, I seen an add for a horse that was for sale.. Is a Bay Roan horse, but they said it is a "Dun Bay Roan" Is this color even possible?.. Because, I do not see the Dun at all.. It does have a stripe down it's back, but I thought roan horses had this marking?
I know that a Roan is white hairs intermixed with a coat color, and the Dun is a dilute gene, but can they also have the "Dun factor" with the Roan color pattern?

The two genes are not mutually exclusive, no. So yes, a horse can have both. This guy is black with dun and roan, so a grullo roan.

Well a Bay Dun bred to a bay roan will give you a Bay Dun Roan.
Depends on the DNA testing there.

But a DUN is a DUN! Zebra markings and all. If there are no dorsal strip down the back he's not a dun.
Regardless... Bay Dun Roan is a real color.
A black dun is just a grullo
A Dunalino is a palomino dun
And a Dunskin is well.. a dun buckskin
Now just add roan in the mix...

The grullo turns into a Grullo Roan
The Dunalino is a Roan Dunalino
And the Dunskin is a roan dunskin

WickedNag is a user on here that owns a bay dun roan.

He's in the second post of this thread.
Just for fun, show me your duns :-)

Awesome, thanks for all of the answers..

So, if the Bay Roan has a Dorsal stripe, it makes it a dun?.. I'm confused, because they have an edited pic, or a pic while the sun is down, and I do see the leg striping, and face webbing, but not in the other pics, where the horse is in normal lighting.. It just looks like a Bay Roan, lol.

It could be countershading. It is where a horse is not dun but has a faux dorsal stripe. Think of it as writing with a marker and the spot where you overlap the color, it's darker there. Countershading is typically blurrier than a dorsal stripe. Countershading only affects the back though and not cause other dun markings.

I've seen the Faux dun in Bays and even Sorrel horses.. I thought it was faux dun in the roans also?
Can a perlino be a dun?.. Sorry, I keep thinking up more questions.. The dun factor has always been mysterious to me, lol.

Dun can be added on to pretty much any color. Now a perlino or cremello dun would be very difficult to distinguish as double dilutes are extremely light to begin with. Countershading (the faux dun dorsal stripe) can appear, to my knowledge, on any color as well. The horse is only a dun if they have the primitive markings - sharp dorsal stripe, leg barring, cobwebbing, shoulder stripe (all dun have the leg barring and dorsal stripe, some may not exhibit shoulder stripes or cobwebbing). Dun factor isn't all that mysterious. It's fairly straightforward.

That is not necessarily true, many dun markings are "interchangeable" I.e: they can have leg barring but not dorsal, ear darkening and barring but not dorsal, dorsal and ear and shoulders shading but not leg barring... you get the idea

I looked up "bay roan dun" nothing.. I found a "grullo roan dun" a perlino dun, a bay dun, classic dun, and my all time favorite.. Red dun. :)

I also read about AQHA saying "bay roan dun" doesn't exist?.. I guess, it's hard to point out on a bay roan, since the face is masked, and it has the agouti gene from the bay coloring.. Or would the zebra striping give it away, along with the webbing on the face?

Can a horse that isn't a dun have the zebra striping? I used to ride an older solid black Quarter Horse mare, that had white zebra striping.. so That makes me curious.. She was a Non Fading black/ true back, if that helps.

Could a cremello even be a dun?.. The only way to see that would be DNA testing, right?