Back in Ye Olden Days... EY might have been using gel coat from the same company the others in the industry used:
Ferro.
I doubt that they are still around, and any gel coat over 20 years old will have UV-faded enough that even a new batch of the same color code number would not really match it. If a prior owner has painted your hull, you would need to know the brand and color code to try to come close to a match.
Are you contemplating a repaint? A close-as-possible patch? I ask because after 20 years and a multitude of patched divots in our hull we finally had the hull repainted with Awlgrip. Solved the problem, but at a cost that commits us to ownership for another decade at least.