I would stay in the neutral tones on all the walls. I would start by getting inspiration from a new rug and pillows. Look at you granite for wall inspiration color.

The color needs to be in artwork, pillows and rug in my opinion. You have a great space.

I agree that the colors need to be in the artwork, pillows and a rug...but you also need to paint a great color....there is one I am thinking of Rattan Basket....Dunn Edwards...a great color. Creates an ambiance and mixes well with harvest colors. Use some textures and maybe one printed fabric for the pillows. Make the pillows different shapes...not all square! Happy decorating!

repeating the color you have in the kitchen could work nicely, allowing the white woodwork/millwork to pop. OR even the color of your couch if you are looking for a warm autumn look. (a shade lighter or darker might work as well)