Dunalino is a chestnut horse with both cream and dun genes.
Chestnut + cream = palomino
Chestnut + dun = Red dun
Chestnut + cream + dun = Dun palomino or "dunalino"
Some dunalinos don't have very distinct dun factor markings and can be hard to verify without genetic testing (unless you happen to know that the horse had a parent that was tested homozygous for dun)
So, the horse you're looking at might be dunalino with light dun markings, or the sellers might have incorrectly assumed she inherited from her sire and she is actually a palomino.