I'm not a pro but I think your best bet is to get a piece of similar wood species scrap, find a few pens dyes or polishes that are a similar shade, test on the scrap wood and let dry. Use your best fit from there and you should be able to seal with super glue and carefully sand it up. If its got a sparkle finish, it will be really tough to match. If its a solid color, then it will at least blend in and be less noticeable. Otherwise, its meant to be played and dings add character!