If you keep the color scheme simple you can leave the walls as they are.

I agree with Dytecture to keep the room clean and simple if you use the pear green on all four walls.
Or paint the other three white, not cream. A cool, crisp white will go best with this shade of bright green. Put your bed with the white bedding on the pear green wall, and add blue, green and yellow accents in pillows, a coverlet at the bottom of your bed, lampshades and art on your walls.