agree, add some color to the room by painting the walls and adding drapery panels.

All the way to right under the crown and a foot beyond the trims on the sides of the windows.

Many colors will compliment the natural stained wood trims, Navy, Greens, ...

BOHO and MCM are total opposites in design MCM simple lines less is more in decor BOHO more is mor ein decor so first pick one IMO. You have from what I see lots of great MCM pieces so my choice would be that direction Drapes are perfect in MCM spaces so a color hard to tell since not much other than blue the pillows are just not good and way too many did you remove the soaf cushions on the back an dreplace with all those pillows ? The room is not layed out well way too much space in the middle . The sofa looks like it has had better days are you planning on replacing it ? For me a nice sofa facing the FP and 2 chairs matching facing the TV wouldbegin to make the space feel les s cold I lkke the blue chair if you could find another to match that would be perfec . Is this only space for TV ? I like the cabinest but not squished together on that wall. Can you post a to scale floor plan please done on graph paper show every measurement and windwos and what is next to this space in your home all that info posted here in peg format in a comment then we have some understanding of things that can work along with choices for drapes . Any chance of the carpet being removed and replaced with wood that IMO will be ahuge step in the right direction

The blue chair looks great with your wood. I'd pick a similar shade for the curtains.

I would go for dark walls...

Pull the sectional out away from the windows

Place a colorful rug on an angle in the room

Select a color from the rug for the drapery panels.

In addition to curtain panels, I'd replace the light cellular shades with a treatment that blends in with the beautiful wood. You could use either wood blinds or woven wood shades, if you need the privacy at night. If not, just use curtain panels.

I’d play up the wood/room by painting the upper walls and only then choose the curtains. But…suggest looking at the big picture first and keep the look in mind whenever you update anything. Imagine your sectional and the wood panelling in this combo.

Adding a rug under coffee table will ground the room.

Long before I worried on curtain panels? I'd want a wood floor, a fantastic area rug. I'd play up my MCM and play DOWN the need for a sectional get a great couch and two chairs.

What is around this room? Add jpegs of the rest, and especially the foreground!......which is what? More pics, all angles and especially with your back to the fire.

Right now, it appears your only source for lighting the room is in the ceiling. Adding floor and table lamps would enhance what you already have.