Telling my date to change his hair

Is it okay to tell a guy youre dating that a different hairstyle would suit him ?
Hes very nerdy looking which is okay and I am kind of dark and alt in my aesthetic but I dont care how a guy I date dresses and styles himself so its not that for me its just that I hate his haircut because it does him no favours. Hes got one of those horribly unflattering top-heavy haircuts that so many men have nowadays for some reason. The kind with shaved all around and then a wave of hair up top.
We met on tinder and he had one photo on where he had shoulder length hair and a bit of beard and he looked great. There was a giant shift from that photo to his other ones because in that one he looked cool and handsome and it framed his face well. Then in his other photos he just looked nerdy and to be fair that is what got me to like his profile because I was looking to meet someone who is far away from being a "bad boy" but I was only found him physically attractive in his first photo with the long hair. Not to say hes ugly because he isnt. Would it be horrible to ask him if he's ever tried keeping longer hair and that I think it would suit his features ? I personally wouldnt get offended by such a suggestion if it was put that way but I am not good at figuring out what may be offensive to say to people and what isnt