Mitch in Chicago's Profile

First, get that sofa and love seat steam cleaned immediately! It will probably cost about $100, and brighten the color and refresh the fabric. Well worth it.

Painting the walls white, or a light neutral, will put a bright spotlight on the very thing you are trying to minimize. The best way to make something that cannot be changed in a room disappear is paint the walls the same color. In this case, I would go either a few shades lighter or about three shades darker. Then add pillows and accessories in greens, along with its triadic sisters, oranges and purples (I'd personally add some yellows, also but I like a lot of color). If the walls are light green, go for stronger, deeper colors in your accessories. If the walls are darker, go for lighter tones in the accessories.

Finally, use the power of white as your ally. When several colors are present, white helps them all play nicely together. White drapes hung ceiling to floor (IKEA is a great place to get inexpensive white cotton drapes), coffee and side tables painted white, a white throw on the loveseat, a few pillows with white backgrounds on the sofa, a few white accessories (frames or a vase) mixed in, white lamp shapes - all of these will "frame" your room, turning the green into a neutral while making your accent colors stand out.