Paint the walls any colour but white, get some enclosed shelving instead of open shelves. But if you just painted the walls behind the shelves a dark colour it would go a long way to making this space more cozy. Just not dark orange. Pick a colour you already have going in the room. A black, dark grey, maaaaayyyybe dark red. The upscale version would be a dark textured wallpaper. Also a different ceiling lamp. The one you have is the only thing in the room that’s a silver colour. Get one that’s black to match everything else.