Painted trim in your great room would look nice especially if it matched your wall color. You could even lighten your wall color to brighten things up. I would also paint the hallway and trim in the hallway the same color as your living space. The question then however is where do you stop? If your doors are solid and you like their look versus hollow-core you might not want to paint those. IMO your furniture layout in the great room looks nice for the space.

Lastly, try pulling your rug out further so that just the front legs of your furniture sit on it.