Facing the same dilemma when I was going to give my oldest the Centurion. A suggestion less damaging to the frame, no glue to wipe off later - saran wrap the entire frame, spray paint it in your best trash fashion and apply electrical tape in the right areas. This can be undone later. However college campuses are bad news, someone already tried to steal my son's MTB but the jerks settled for the handlebar grips. I had removed the quick release from the seat and substituted it with an allen bolt and locknut. He did a good job locking it up with U-Lock cable. I've seen bike on campus with the front inner tube partially removed. If the buggers can't get your bike they would vandalize it for spite.