It's a rental so buy something that you can take with you that will work in your next home. Just stay with green and white. You may not be able to change the panels, but you could add to them where it can't be seen from the outside. Add white to the outer side of the blue panels. Then get a navy and white throw pillow for the accent on the white sofa.

I would love the rocking chair too, but way too expensive for me, unfortunately!! Yellow could be good... hmmm, will have a look, thanks

Accessible Beige by Benjamin Moore would be a good beige as it has a slightly pink undertone that would pick up the color in your pillows. I wouldn't go a light blue, as that seems more in keeping with bedrooms, IMO.

It looks like you have wallpaper on the wall behind the sofa. am I right? How many walls are you painting? Post more pictures of the space if you can. My inclination would be to go deeper like BM normandy, black pepper, taos taupe, iron mountain… but hard to say with seeing so little of the actual space.