Molding. Molding is a great solution for adding architectural detail on any wall space. Instead of going only around the base or where the wall meets the ceiling, consider several horizontal and vertical panels for a contemporary display.
I noticed the fan you have installed in the ceiling. We have a steam shower and I find myself having to clean the travertine tiles/grout so often and we leave the shower door open 24/7. Is the fan the only thing you need to keep a steam shower free from mold/mildew?
against mold the upper window tilts out allowing the steam to escape after use. That is why we installed a second fan right outside the shower door.
You should consider purchasing mold remover from Italian manufacturer Fila. All our customers are happy with the product.