This is probably an epoxy finish. Clear epoxy resins (like these) can be tinted with artists’ oil colors. You would brush the resin onto the repair, allow it to harden (at least 48 hours), then use progressively finer sandpapers and a sanding block to level the patch (using water as a lubricant). You will end up at something like a 1200 grit paper, which will leave the finish smooth, but cloudy. To restore the gloss, you hand rub with rubbing compound.