"Dishevelled' would definitely be insulting. It would suggest he rolled out of bed and didn't properly get himself ready for the day.
Kind of like the kids, when I was in college, who came to class in their pajamas. I might
be one of those kids.
(Although I at least bothered to change my pants so nobody would know right away that was my pajama top.)
Maybe he could say Albek's hair is very "unique" or "distinctive"?