I believe the accent stripe is just the C stripe the goes along the door. The visibility group consists of a remote mirror and day/night mirror (thats all I can think of). I am sure someone will correct me if I am wrong.
the accent option on a fastback is simply a 1/8" wide painted on pinstripe that runs above the body lines from the front of the fender around the quarter indentation and back to the fender. on coupes and convertibles, the option meant that the quarter ornaments were not installed.
the visibility group in 1965 consisted of 2 speed wipers and windshield washer system, driver side remote mirror and a day/nite rearview mirror.
I have a 66 with the accent group. It consist of a stripe similar to the 67/68 "C" stripe, but only about 1/8" inch wide that starts behind the headlight ext. on the fender and goes back and around the 1/4 louvers (scoops) (behind the doors), and back toward the front wheel wells. The chrome 1/4 louvers were deleted with the accent group, and the stripe color was usually the same color as the interior. Someone had mentioned that the rocker chrome trim were part of the accent group on the 66's, but I'm not certain on 65's.