They have some really nice textured wallpapers out that look like bamboo or grass. I'd consider that because they are light and airy, but fit the theme. Regardless, I think I would lose the pale yellow walls and go with a mossy green and accent with darker greens like billiard green and/or emerald green.
I'd go with the jungle theme! Use white sheers that look like mosquito netting on the windows. Use artificial (I would use real) branches to hang them on, and dress it up a bit with greenery. In all honesty, I would probably paint one wall as if it were the african savannah. Blue skies with clouds, jungle-y type area in the distance, grasses in the foreground. I would probably add an elephant or two, maybe at a watering hole, and some gazelle or something way off in the distance.
Have fun with it! You can project the images onto the wall with a rented overhead, pencil draw them and use acrylics to fill them in and blend. Oh, I would LOVE to do this room!
Hope you can use some of these ideas!
Hugs, Didi