I love the chairs they have always been some of my favorites:) With the dark floor and most dark furnishings I feel like a cream or colored area rug would elevate the space and add interest. Are you going for a monochromatic look? If so then let only the art have color. For the pillows on the sofa the black pops nicely off the cream add one more pillow to each side or 1 to the sofa and 1 to a chair with a metallic look and a texture.

Also I feel like the floor lamp is all wrong for the look of the space. Something with interest would be wonderful and more contemporary. Glass and metal cocktail table a plus:) It also looks like you can hang a light over the dining table, another great place to add interest.

Art: color over the sofa and large piece and over the chairs more sculptural:)

Those were some great suggestions!

Pillows are fine. They match chairs, window, floor. Love the ideas above.