Is it a greasy type of face paint?
I’d scrape/rub with a dry cloth as much as you can get off then rub a little neat washing up liquid -just a little at a time-dry clothing it off & keep repeating until most of it is out then apply water to rinse the washing up liquid out.
Or, If you have a pale face cloth/fabric dish cloth maybe rub a bit of the face paint on it and experiment what gets it out.