Genuine Grasscloth does not hold up well in moist or high traffic areas. Why don't you just paint a high glass navy on that wall to match the high gloss tile in the tub area?

Do you have a shower curtain? That would give you all the drama/more color that room could handle.

Painting that wall navy should not be a problem. My only concern would be that it would darken the room considerably, however it is just paint and you can always paint it white again! Perhaps try to find a nice vibrant picture with navy/blue colors to see if that doesn’t satisfy your eye. I agree that that wall is somewhat bare….

I agree let the floor be the star and I would check out glass shower screens for the tub instaed of a shower curtain.

I agree with other posters - wallpaper would compete with the floor tile and would be overkill.

I love your tub, who makes it please? Also the floor tile is great!

I am not sure who makes the tub! It was in the house when we bought it!

It is rather plain as is, but would try a nice piece of art in that space before painting. Also, please hang a second towel on the rack…the single lonely towel is adding to the sparseness!

Love your floor and vanity combo!

If you go with wallpaper, a subtle pattern would be best with the floor. Note that a damp environment may not be the best for wallpaper, but if you want the same type of effect that may be more durable, you can try a painting technique that gives the same look and feel.

https://www.home-dzine.co.za/decorating/decorating-dragging.htm

If you go with a coloured wall I would do a white shower curtain and white towels.

Agree with some art on that wall and letting the floor remain the focus.