Here are room photos.

The right Sage green would work with the adjoining room wall color, also work with your overall grey/green decor color/palette - as well as with your red furniture. Try some samples. Samplize.com

Behr, ’Morning Zen’

Behr. ‘Sage Brush’

Behr, ’Sage Wisdom’

Thank you . I hadn’t considered using any of these greens but they really look nice.

Lyn is right. Prime first, to make it easier to assess your samples.

I like the idea of a green if it can be more subtle and not like Christmas year- round.
I also love some types of khaki neutrals, more toward buffs and tans, with the dark red furniture, but that might be too warm for your palette.

I was worried that a green would look like Christmas in the middle of summer. I usually stay away from tans and have green and grays throughout the first floor.

I sugget before trying to figure out a color prime and prime againre to kill the red or every color you choose will look awful Then if you want a nice neutral I use this but cut 25% It is BM and I use it often.

Like the green idea

Start with your sofa as knowing that color is so important before settling on your wall paint. Wood floors are great and I’d completely ignore that grey carpet since it’s going. Hard to ignore the patterned tile in the adjacent room though so best to post photos of both spaces as well as what the existing neutral wall paint is that you’re keeping.

I’m planning to reupholster the sofa and can pick the color later. The flooring in the adjourning room is actually plywood I painted 13 years ago, when I was younger divorced and looking for a cheap solution. I am planning to replace all of the flooring on the first floor at the end of summer when I have finished my outside projects. ,

Goodness— if you are recovering your sofas and putting in a new color of flooring, you’d want to pick those out before nailing down the wall color. Not saying don’t collect samples for a mood board and possible color schemes to be considering, as you can use your “ maybe” options for floor stain yo help think about colors and maybe - sofa to think about walls and aspirational wall looks to inform those others.

But it’s a total game- changer to be discussing walls for red sofas & then, change the sofa color.

Another reason to prime the walls- unless there are serious economic disadvantages such as hiring a painter who can’t do the work in stages or expects to prime and then have your color choice shortly after, & you’re not ready.

Ask the paint guy to add some gray to your primer, it will reduce the number of coats needed to cover the red. If you use white over the red, the first couple of coats will still look pink. Been there, done that.

Agree that you should choose your flooring NOW. Before you decide on a finish paint color for your red room. BUT, in the meanwhile, DO prime those walls. As deegw says, it will take MORE than one coat of primer. Then….floors…then…fabric choices, rug. Then final paint for the room. But I do like the idea of a light sage green. It won’t read “Christmas!”

Agree generically with that( not an expert)- to cover a dark color there has to be some “ color “ in the paint ( all that stuff about chroma) vs coats & coats.

Me too @deegw.

Keep in mind it's usually not worth it to recover a sofa unless it was very expensive or an antique to begin with. Reupholstery can cost as much as a new sofa. As for the wall color, you should be choosing it last as the other commenters have said. If you like the lighter color in the adjacent rooms and don't feel like changing it after you replace your floors then the easiest thing is to just use the same color, or the color that is two shades darker. You're right about greens - I love green, but after a lot of sampling in my previous house I discovered they always looked much more green on the wall than on a chip, so choose something with subtlety if you decide to go in that direction. BM Gray Cashmere 2138-60 is a gray-green mid-tone and might be worth a look.

Thanks everyone for the advice. I think I will just go ahead and prime just to get rid of the red paint for now and wait to decide on color after I decide on floors and and sofa fabric.

kandrewspa I get your intent re: the costs of re- upholstering being not at all cheap, and I’d add that a lot depends on whether there is a skilled shop in the area, because you’d want to have confidence that the result would be good.
But the cheapest option might not be the best criteria.
There $$ and there’s value to the owner. If the sofa has good FEATURES such a size, style, arms, cushions and is adequately sturdy ( to make it through another decade or so) , it may be that it’s hard to find something comparable locally to try out in person, new styles may not suit as much, and fabric options may be more limited, and so on.
So sure, I’d shop around a bit to see what’s out there that could be equally good or an upgrade, especially if I were in the market for a neutral that’s in common stock, and planned to get my color& pattern kicks from other decor, or if I wanted to see if I could be pleasantly surprised, or if my sofas were never my favorites anyway , or if I had access to several really good lines of upholstered furniture in nearby showrooms.
I just wouldn’t make it completely about price A vs B or appraised value.
It is a shame though that reupholstering is not an especially economical option.

Good call to figure out floor and sofa first.

The sofa is the perfect size for the room and in exceptional condition. I have used someone locally to upholster chairs for my office and make covers for my outdoor furniture. He does a great job and is very reasonable. It is worth comparing the cost to a new sofa though.