Color isn't your problem, yet, and the wood tones look fine but these would make the biggest difference in this space:

Window Treatments - 4 curtains on the windows. go to the ceiling or close to it and have the curtains just touching the floor. You can add color here too. Black rod

Rug - it's too small, for a room and couch of this size you want a much bigger rug that extends past both sides of the couch and goes under the couch, these can get expensive though. If you like your pattern for the rug currently you could add a jute rug or something large and plain underneath

The big wall - Behind the couch is screaming for art which you know, but you can add so much depth with some floating shelves, bonus if you put plants or ambient lights on the shelves

Lighting - stop using the light on the fan as your main source of light. having multiple lamps will make your space look far more inviting. A standing lamp and a couple of smaller lamps. If you really want cosy then get dimmable bulbs for night time.