What color is the interior? If you're not planning on changing that, make sure your color choice matches nicely. For example, a blue or parchment interior might not go well with orange, but black or red interior would work.
What is the cars original color? If you post the complete info from the driver door tag on VMF, we can tell you. Sticking with the original color can be good, because then all the nooks and crannys will match well.
Will you be stripping the old paint down to bare metal? If not, you may want to consider a color close to what it is now.
Are you concerned with "correctness"? If so, stick with a color that was offerred in 65. If not, the skys the limit.
Personal opinion ... I'm not hot on the bright oranges for that year. Here's a pic of my coupe (original silver-blue) and my buddies Vert (non-vintage green).
Good luck, I know how tough this choice can be (but I bet you could care less what color the drapes in your house are!).