Are you expecting that outside light is enough to illuminate a room?
What would happen in real life?
What would happen if you were assigned to photograph this room for a magazine? Yes. You'd call a real photographer. He'd bring lights.
Try some of this:
Place a general light source up and to the right of the camera. max falloff. yellow.
put one under the floor. about 20 feet down . maxpower blue tint
play with the relative and absolute intensities until you are satisfied - then you have a system for a room.
Shine a window light up to the ceiling from about 7' - yellow.
Shine a window light down from the ceiling from the ceiling height.- mauve
Add more ambience, but save that for last - to make up for deficiencies in the other light.
Share the result.
Dwight Atkinson