The cabinets look lovely stained. I would keep them as is, especially since they match the kitchen cabinets. You could paint the backs of the shelves as suggested above.

Adding lights to your room will make it brighter.

Leave them as they are as they add a lot of warmth and charm to your room.

You are covering up more than half your window. Of course your room is dark! If you don't want your neighbors seeing in or the view is an eyesore, get very sheer sheers.

You can also use silver leaf on the foam core to add a reflective backing to the cabinets, that will help bounce light around. If you antique it, it won't be so bright, but still do the job.

The darkness in that room is from your window treatments, not the wood bookcases. I would leave the bookcases alone and re-think the window treatments.

If you simplify the decor on the shelves, using fewer items and more open space, the whole wall will look more fresh and light like your fireplace decor.

I would leave the stained cabinets and make some minor changes. I would remove most of the items on the shelves. I would change out the wooden shelves to glass shelving and then install two puck lights in the top of each cabinet. I would probably also use some tape lights attached to the top of the cabinet casting light up toward the ceiling. Make sure all lighting is dimmable. Return only a portion of the items on the shelves - keep them simple, clean looking and uncluttered.

Declutter Shelves. Glass shelves I think would be terrible to keep looking clean (my opinion) Bring more focus to the area above the fireplace by adding a lovely painting or photo - large with depth. Add some hardware to your cabinets. Find some pretty lamps, small enough to place in a couple of the shelves (balance light on each side). If no outlets use battery operated lamps. Remove the TV.

Hate to suggest painting real wood cabinets but, yes, painting them white should do a lot to lighten up the room.

I had been thinking about my own built in bookshelves. House in 100 years old. I will not paint. Here’s what I would do: De clutter. Add plants. Remove TV. I hide mine. I don’t believe in painting all wood. Walls, yes. I also absolutely hate kitchen marble and granite — butcher block or tile, yes. I will be working on my house so I will not add photos now, but I will once I’m done with upgrade and preservation. Best wishes.

You could but not white.. paint them a fun color to make them a focal point.

Or if you do white.. paint that wall a COLOR to make it a focal point. That whole area is bland..