First of all, the mirror above your sofa is too high, it needs to be about 4-6 inches above back of sofa. Choose a wall color from the lightest color in your rug.

All your furniture is neutral - so you can go with any color you want. What's your favorite color?

Here are a few suggestions (other than paint color) to improve the look of your space:

1. Lower the picture above your sofa so that it is 6 inches up from the top of your couch. Lower the two pieces of art flanking your window (about 10 - 12 inches).
When pictures are too high they lose their connection with your furniture and move the eye towards the ceiling.

2. There are too many cushions on your sofa - reduce to two or three - it will look less crowded and bigger. I bet when people sit on it they remove some of the cushions?

3. Remove the valance from your window and keep the panels - you've got a beautiful window and source of light there - removing the valance will open up the space. If you have a budget, replace the window dressing with a fabric Roman Shade.

4. An open leg upholstered bench would look fabulous in front of your window and provide extra seating.

5. Replace the two large pillows from the corner and replace with a nice big plant.

6. You need to put lamps and small objects on your side tables - they look a bit lonely.

It is difficult to tell what colors are in your area rug - could you describe pls? Looks like beige and grey?

Don't forget to let me know your fav color. What is the color theme in the rest of your home?