I’m not a designer but I think your instincts are right. If everything else is super light I agree the sofa will look too dark and heavy. I think a light, warm neutral paint would be great, and accents of blue would make that gold sofa sing. I think your existing neutral walls look okay, actually. What if you just tried painting the red accent wall a nice mid tone blue?

Comedy of errors (only after we had a few drinks was it comedic) 1. We greatly underestimated the effort to paint textured walls, especially on the ceiling. That and we're 15 years older than many of the projects we've done the past. 2. Turns out we got the wrong color paint. I'm not sure why I had a different color paint stuck in my head and even though I checked color swatches I still got it wrong. And now that we're going to pay someone to do it I definitely want to make sure the color is right. Only after I came back to this post did I realize I gave the store the wrong color. We're going to suck it up and pay someone to do it which is good because that also includes trim and doors. Although now I have to take a week off of work. Good news: we can donate the paint to Habitat for Humanity ReStore.

We have the daylight LED lights through out the entire house, so I think my lighting is okay. Here is a current picture (my cabinet doors are being completed today. Ignore the back splash the previous owners picked the finishes on this house with their eyes closed! The back splash will be changed next year. The yellow undertone doesn't fully come through in the picture but you can see it in comparison to the door. My plan for the door will be to paint the trim to match the cabinets and find a dark grey that compliments the room. Thoughts?

All pretty colours. Top Sail is in the Green Hue Family the others mentioned are all in the Blue-Green Hue Family. Lookout Point is the most greyed of all the colours. Tradewind, although almost 9 points darker, is a more colourful colour than Lookout Point. Any of these colours mentioned will look pretty with those gold decals. It may help you decide by thinking just how much contrast you want the decals to have with wall colour? Subtle variation which you catch by the change of light as you move, or a strong contrast? When you narrow your choice down, I would paint up a couple of boards and apply the decals too. Place them vertically in your space to match the plane of the wall.