I think some vinyl wall decals of branches etc to complement the tree on the curtain would be fitting.

The is such a bold color. With a wall being so bold and having a hugh graphic print on the shower curtain, my advise is to stay simple! I think if you found simple art for above the toilet. Something black and white, possibly a figure piece of art. Z-Gallerie has some nice, inexpensive art. For the other wall by the shower curtain, I love doing what I call "art-but-not-art". This can be a wood sign or sculpture. Sometimes I love finding a rare find at a local consignment store or flee market and paint it white lacquer.

Lastly, the one wall you left white in the bathroom, try painting it green, it will help unify the space and make it feel a little larger.

I hope this helped!

Black framed something....

ideas..except the tree one prob. doesn't have the right green in it

Less is more! Hang some white towels on those hooks. The eye needs a breather from time to time.