try chalk paint
with some love and dedication this can be painted real thin but if you try it on thick it won't look as good and it will lose some of it's functionality. (Yuck!)
Simply use some thickish wax, apply to the black strips and apply some chalk paint to the white and cover the edges with more chalk paint for a more amazing finish!
Great idea 😉
WARNING – Black chalk paint on a white surface is very potentially hazardous to human health and can be very dangerous to pets, especially if used on older masonry or painted surfaces.
For safe use of this topic, read my information page on tetchy chalk paint before doing anything!