Would help to see room layout with all measurements, along with furniture placement you have planned.

Slats and shiplap and Western flare with MCM - I’d be concerned about it looking very disjointed and the color is already a strong statement. See below and then imagine your color and two treatments.

Sounds like couch will be on shiplap wall with tv across and do you have any other furniture for the room? Can you provide a picture of the entire open space?

Nothin MCM modern about shiplap ever and that green is awful (sorry) and for sure overpowers the sofa color . Stop right now and show us the whole space and a pic of what you think is MCM Post all of that here in comments DO NOT start another post.I went to your idea books and not much MCM there so I need to know what is in your mind .BTW wall color is the last choice you make not the first.

In the mid-century, plenty of types of furniture in western decor had MCM lines. A Brandt is probably the most well known, but there were many others. And plenty of houses back then (on ranches or in the ’burbs) had shiplap or paneling.

So yes, the MCM-inspired sofa shown would work fine.

Please show all of the room, what other furniture you’re using (or thinking of using), and if you’re married to the green. I think that particular hue might be challenging to work with.

I would not do different treatments on other walls with the shiplap.

ETA: Somehow I missed that this is in an open floor plan, please do post all of the room as well as adjoining rooms. Much more context is needed here to help with suggestions. Is this a new build? What will your flooring be?

I love when people use color but I think that’s a very difficult green to live with. Paint it now with a couple coats of primer and get the room a bit more neutral before going ahead with any other changes. I like Jilly’s suggestions about furniture.

I’m a green-all-the-way person but that particular green is hard to work with. Are you open to a different green? In the MCM world, there are many pretty greens but they often lean more olive.

I agree with some of the comments that are a lot of beautiful greens that are much easier to work with in a space. The color that you have right now might be a bit too much.

Thank you for your advice on the green. The house is under construction. There is a lot losing on right now. I used Benjamin Moor paint. I don't like the green that was suggested does anyone have any other suggestions?

It’s truly impossible to say without more info. What I’d do for now in this case is paint it a neutral color until you’re further along in construction.

Is your flooring picked out? What rooms are open to this one?

I don’t mean this harshly, but no one can possibly know what green would work with only seeing one corner in a house under construction.

If you haven’t already, start gathering inspiration pictures and see what appeals to you most. Houzz, Pinterest, and Instagram, as well as magazines, are great resources.

Or consider hiring an interior designer.

Congrats on your new house, btw!

The flooring is light the rest of the walls are Benjamin Moore’s Sea Salt is a light gray with warm undertones all the hallways the kitchen ( white cabinets.) with the rest of the house

Hold off on any more accent colors. Sea Salt is great for most rooms but may force you to stay in the cool family (vs warm). But it’s a great color. Many people have used it in bathrooms and kitchens.

I like the direction you're going but I don't think that bright green wall fits. I would cover it with primer ASAP because the strong color is going to reflect on everything you put in that room and make the choices look "off".

Rooms that are fully decorated rarely need different colored accent walls. Concentrate on things that will enhance the people space - rugs, lamps, side tables, furniture, etc. That's the part that counts.

Thank you

If you decide to repaint, consider adjoining spaces, flooring, overall color scheme when accessorizing.

Look on line to get a sense of green undertones in rooms and how light/dark you want.

Ask paint consultant for help, bring home test pots of your 2-3 favorites, and this article might be helpful with undertones.

https://livendesignco.com/blog-2/2021/3/12/best-green-paint-colors-for-the-home

Before going any further into details, I would reconsider the bright green. Below is an illustration where I've integrated the sofa you're considering.

Also note that not all walls are green...

Authentic shiplap (which yours is not), has its history in maritime. Ship lap, designed and built specifically for the exterior side of boats, to keep water out. It and western style just aren't related. Strip off the green paint and stain the wall.

I’m a green-all-the-way person but that particular green is hard to work with. Are you open to a different green? In the MCM world, there are many pretty greens but they often lean more olive.

Oh yes

Thank you

What do you think of High Park green
benjamin moore

I show below the High Park green you're considering. Based on the image below, I much prefer a darker green such as BM Vintage Vogue but I haven't been in your room nor do I know if you intend to paint all the walls or not. What ever paint colour you decide on, make sure to test it on your wall before going ahead with the entire project.

Maybe something from the same color strip as Sea Salt like Retreat, Pewter Green, or Ripe Olive.

https://images.squarespace-cdn.com/content/v1/5b63984d4eddecebc8191405/1615928354850-A8EHBP07ORRL5RAC5IBM/deep+greens.png?format=750w

What about vintage Vogue

Vintage vogue

Dark teal? Two MCM examples and a possible palette…

If you are set on BM sea salt walls - BM has given you a coordinating green that will work with it - Lush….get samples of all to test in space with major items like floor, rug, sofa. Otherwise you’re just shooting fish in a barrel.

Posting photos of the rooms after your Sea Salt paint job will get you a lot of specific color/furnishings/layout help. I agree that the soft olives will be gorgeous with not only Sea Salt but your MCM ideas.

Thank you.

I really wouldn’t choose a particular color green until you have an inspiration piece to work from - a rug, a throw pillow, a piece of art. Starting with a very bold wall color like this really locks you in and, as you’re finding, makes it difficult to find things that “go” with it.

I guess I missed out on the BM Sea Salt paint colour but yes, BM Lush looks good as a coordinating colour and is dark enough to work with the sofa you're considering.

But remember to test... test... test!