Interior Design of living room & kitchen with very little sunlight

Looking for an interior designer for consultation and ideas. Our open concept living room + kitchen has very little sunlight, so the room is quite dark throughout the day. The challenge is to make it cozy and inviting, maybe embrace the darkness? Add some colour? Architectural interest on the wall? We've tried a few things but reached our limits.
The place is only rented so we want a budget-friendly solution. If you are Berlin local, we're happy to invite you to see the place in person.