https://ruggable.com/products/jonathan-adler-inkdrop-lapis-blue-medium-pile-rug?size=6x9&system=rug-sys

Yes, to @Lyn Nielson's rug. You can buy peel and stick trim to mimic paneled walls. Paint them before install with the blue of the walls. Change throw pillows to dark blue and add art over sofa. (Floor plant is a good idea, from photo). Keep the chairs for now.

Are you leaning towards a light or dark rug, patterned or solid? Once you add navy in some form, it will all come together.

I'd prefer lighter just because the dark wall is making the room dark already. Can be patterned but given the floral chairs, pattern would need to be subtle.

Agree blue in the rug will make it come together. Was wondering if there are other color schemes I could possible consider.

Maybe a light neutral with a subtle pattern (won’t compete with the floral chairs or your flooring).

I will play with this arrrangement.

Many people have suggested painting the entire wall blue. And I agree that break looks awkward. It is a secondary project right now :)

I had a similar open 2nd floor living room (minus the fireplace) and had tried the couch across the railing. Seeing its back from below was not ideal and the openness between the two floors was lost. I also found couch/large art on the far wall grounded the space. It’s easy to test and maybe wait to purchase the rug until decided as the size might be different.

Suggest a large plant on the left and floor lamp on the right, as the dark corner will benefit and be sure to add substantial art.

Try the chair/small table on the left and the two chairs facing, which will help to create a nice balance.

If interested in suggestions for the fireplace (it‘s an important feature) a picture would help.

That is a lot to tie together. Will suggest a white rug to act as an anchor for everything.

Your neutral rug idea will work well. Plus, you will be able to use it in other rooms, and in other homes in the future. How long is your lease and how long would you imagine staying in this home? Rugs are expensive. Get one that will work for you for the long term. Purchase less costly items, like pillows, to tie int0 this blue wall. This is a lovely little space.

Appreciate all the useful advice. The floor plan is tricky. Sharing the picture I drew.The living area opens into another space labeled 'dining' - which I have converted to a TV room. The blue sofa in the TV room was bought to bring the blue color of the wall into this connecting space.

I would go with some modern rug like this one from West Elm

Some neutral/natural rug would work as well