Thanks馃憤 not something I would have thought of.
It's not ideal, but... I decided to try it as a temporary measure as I didn't have much faith in my ability to paint neatly and it's still there. So I don't really see much worth in trying to paint it and potentially making a mess. Also, if you do have paint still in there but it's faded, the pen sits on top and makes all the markers look the same.