The hulls are technically not “painted” from the factory, they are gelcoated. That is essentially a pigmented polyester resin topcoat. The best approach would be to cover your repair with gelcoat. You can get white or neutral gelcoat and then add pigment to match the surrounding color (although getting an exact match can be tough). Keep in mind that you need a barrier between the gelcoat and air in order for it to fully cure. So either spray PVA after you apply the gelcoat or add a small quantity of liquid wax additive to the gelcoat before appllying. Also keep in mind that gelcoat will bond best to polyester resin (not epoxy), so using polyester rather than epoxy for your repair might be prefered. Polyester is what the rest of the hull is made of.
I’ve had good results using materials from here:
http://www.uscomposites.com/polyesters.htmlsm