I would recommend against paint, it chips so easily over fiberglass. If you do go the paint route, make every effort to apply the coats as thin as possible and prevent unnecessary layering.
When I was manufacturing snowboards, I had the best luck with DuPont ChromaClear. It sticks really well to bare fiberglass, is extremely flexible and tough, and tolerates rapid extreme temperature changes.
I, by no means consider myself an expert, but I have sprayed a lot of paint and gel. It's all about gun settings and technique.
Todd (TRG) repaired a gouge in the side of a boat for us. The gouge went across multiple colors, including a fade. From where I was working, I was able to observe the entire process. By the end of the day, if I didn't know where the damage had occurred, I would not have been able to point it out.
If you're interested, I can PM Todd's contract info.
Cheers,
Joe