roan. definitely not a grullo imo
this is my friends Grullo gelding in the summer the most he ever bleaches out Zuny.jpg
and in winter he usually gets lighter on his back and rump but this pic doesnt show it Zuny winter.jpg
and they will have some or all of the following markings- dark face, cobwebbing around the eyes and forehead, dark mottling on the body, leg barring (sometimes called tiger striping), dark ear tips and edging, dark ear barring, dark shadowing of the neck, dark dorsal and transverse striping, and dark mane and tail guard hairs.
as you can see with my friends horse, he has the dark face, dark eartips and edging, leg bars, dark dorsal and the dark mane/tail
which i dont see with your horse but thats just my opinion. i could be wrong