We use matching shoe polish, the kind in the can. Rubbed it on, and then off. fills in the holes pretty good. There are also crayons you can buy for the purpose. I would be willing to try anything of the same color, for the purpose, let it dry some, and rub it off. We debated a long time before buying leather, for that very reason. Good luck!
mm
"Cats are like potato chips, you can never have just one".