What a fun room! I could see a pretty, soft leaf green on the walls. Would lend a bit of a natural feel to the space.

A light creamy yellow.

I would do a fresh green color. I recently did a spare room for my granddaughter in green and coral and loved the result. I used BM Apple Blossom on the walls.

That's a gorgeous green, and much as I was envisioning.

Ironically, I have used a similar color in the rest of the house, though probably not soft enough. The color was chosen to mimic the palm garden outside the windows.