https://www.etsy.com/listing/476520815/home-decor-wall-art-gallery-art?ref=shop_home_active_15

Great space! I would consider replacing the shades to a more modern option and I think you need some softness and horizontal elements at the windows. A simple metal pole with grommet draperies would be a nice touch. Also, if you aren't fully committed to the artwork, something a bit more bold and colorful would be stunning. Love your chairs, consider perhaps a rug to separate them from the floor.

You could go with a large piece of modern art and I know you wanted color, but I think rust/black/gold/white would be stunning and go for impact in the design. The other idea is a collage of interesting pieces. Then I would add some modern/sheer black roller blinds to complete the look.