If you paint everything one color, it will all blend together. You won't see the panels anymore. Is that cedar siding for the outside of a house on the wall in the back by the couches? You can remove that.

What is your definition of modern? Do you mean all one and fresh? I'm asking because the furniture you have isn't modern. The flooring isn't either.

So, pick a nice color that ins't dark and paint it all the one color, see if you like it.

If you don't, you can change paint easily.

I think it's cool [minus the shake roof].

Modernize the furniture. And re-arrange room.

Paint wall dark to make it blend better. OR Paint Murals in each opening. Or Hang Pictures. Make it have a purpose?

Keep the floor too.

I am not a pro.

One will post a good idea but hopefully they'll also say DON'T paint the Walnut.

Keep the trim. Your bigger opportunity is furniture. Go solid color in the future and ditch the plaid. Your wood tones are clashing too. Pick a geometry too....you have square, arches, etc. This results in the eye and brain going “too much ish going on here...SYNTAX ERROR!”

You could do some really pretty wallpaper in the columns..Anthropologie has so many options.