roman shades in some type of pattern and color.

couple of wood shelves w/plants on the one wall,

and art on the other

you could also do a wainscot in the tub area,,,keep it even w/the window. do a cool tile like they've done here w/the fish scale..

or do an actually wainscot in white and some wallpaper above it

over the toilet, some art, or shelving like this

look at the black and white pictures and the towels.