Something Bright! This needs some color! You could do the walls a beigish color, but then do one wall as an "accent wall", it could be just about anything, blue, red, green, you pick whatever you like that you can live with...and then get some fun throw pillows to go on the couch, make it bright and bold!
I have the same thing a light brown couch and grey carpet, were painting the walls "old gold" from the debbie travis line of paints. I think if you want to go warm go creams and golds and if you want to go a little wild go orange, or maybe a burnt orange
You need to use standout colors, ie orange, gold, or a greenish paint would work wonders in your room, whatever color you use also get a throw to go over the back of your sofa...the best to you
I have a grey fabric sofa and brown carpet and am thinking about some leopard print and pink pillows......do you think this would work??