Yes palominos can have counter shading. I'm just about 100% sure this horse is NOT dun, and Im even really doubting the Palomino portion of it as well.

To be dunallino, his genetics would be ee CRcr D?.

Ariel: This women, who broke your heart. Do you still lover her?
Hook: Yes
Ariel: Then swear to me on her name.
Hook: I swear on Emma Swan