Since the wall color is so cool and the sofa is a warm color, you'll need to bring in warm and cool colors in your accessorizing. I think blues and grayed purples would work. You'll have to experiment with how light or dark to go, but I would probably stick to medium to light accents. Prints that incorporate 2-3 colors would be could.

That bump out in the wall is going to cause a problem with the art. I don't have time to work on it right now.

Here are some visualizations of rugs:

Loloi rugs have amazing selections in the green/tan colors. Anastasia is a great transitional style and the price is reasonable.

http://www.wayfair.com/Anastasia-Light-Blue-Mist-Area-Rug-ANASAF-10LBMI-LYH8104.html

I would stick to more soft/solid pillow options (more versatile!) and you could always add a good throw in a pop of color or pattern!

http://www.westelm.com/products/cozy-boucle-pillow-cover-blue-lagoon-t2083/?cm_src=pillows||NoFacet--NoFacet---_-&

http://www.westelm.com/products/cozy-texture-throw-t2155/?pkey=cthrow-blankets%7C%7C

Both red and certain yellows will pick up your green in the couch. For the pillows that are green, so with light and bright green. You want to go with warm colors, not cool ones, unless you are going for a grey look in your couch. I don't think you are.

I would go with a couple patterns, but more solid colors to not make the area too busy.

http://www.houzz.com/photos/products/query/pillows-with-yellow-and-red/nqrwns