Stealth decal issue

Minor thing but one of the decals on the 575 deteriorated, looked like mold was growing between the decal and the fiberglass. Only one of the decals did this, all the others look clean.

Wondering if anyone else has had the problem?

It was easy enough to get the decal off gracefully with a plastic blade, now am wondering what would be the best solution for getting the glue residue off and not damage the gel coat?

The other side

My go to is goo gone when removing sticky sticker residue. I would apply to a small area first to be safe that it would not have any negative effects. Good luck