Adding a rug to the floor is not going to fix what's wrong with this area. Please look at the revised layout and the art that has been added to the wall. This layout works better and the art picks up the color of the accent chairs. Is that really a trophy on the bookshelf:? How amount a lamp instead?

This is a pretty room with too much Hobby Lobby decor. You've got vases of sticks in display niches. Reminds me of a hotel lobby. Find something you love and want to look at every day to put there. I chose a couple of ethnic artifacts, but it could be art glass, or antique pieces. Here are a couple of rugs that will work better in your room:

I would keep the bookcase shelves consistent with the bookcase as you have a couple colors going on already and I agree if you add many art pieces to that long wall that will bring in color and add some business.

I find it's best to go to a local furniture store to try out chairs. Look for small scale club or swivel chairs. There are usually a lot of fabric choices. Etsy has great pillows. Your palette is neutral so pick a color that you love for the accent.