Even a "nonwet"area will be affected by steam. Also, that texture behind the sink and toilet is very hard to clean and sanitize. If you’re set on keeping it, I’d get a color wheel and match the darkest color, and find a solid, large format tile to match that. Might as well let the travertine be the star.

I would try to lighten it up. Something like this

Take the lightest colors out of the tile . Keep it a simple pattern. Even go with large format tile so that is stays " quiet" since the travertine is so busy. You could even do the floor in the same tile like shown here.

Good luck!

There is a study adjacent to it that has been converted into a bedroom and now adding a standing shower and modifying the space .

@Debbi we possibly could but will probably get custom doors instead...

Also the bench is more to put a foot up on while shaving than sitting 😉