For a while I rented a condo unit that had similar carpet throughout (and matching green tile in the bathrooms). If a large element that you can't change isn't to your taste, the key is to avoid both playing to it and playing against it. Specifically, do not use a wall color that is a direct or near complement complement of green: that is, not red (or pink) and preferably not orange or purple, either, because all of those will make the green stand out instead of recede. I have deliberately used green carpet with pale yellow walls, but it was a grass green, not avocado. In this case, I would prefer a greenish khaki (not taupe - too pink!) or beige, which will somewhat blend with it. And not too light; the color has to be strong enough to withstand the green light that the floor will reflect. BTW, if the element that you can't change is a pattern rather than a solid, using more of the color that stands out too much is a way to tone it down. The same rented condo had bathroom cabinets clad in laminate in a violent gold pattern (this was against the expanse of avocado green tile), and I found that using a gold shower curtain and towels calmed it, because it made gold a background color rather than the foreground.

I would not do an accent wall. That's trend that's passed, and there is rarely a good reason for one. With that color of carpet I would avoid colored walls. A warm white would be a good choice, which will give you great leeway with color in your decor.

-call it emerald. will instantly feel elevated)) I'm serious btw -can you hang wallpaper? they sell several cool ones that are temporary..easy to take off -if you can't/rather wouldn't...pick the color that subtly echoes that emerald..soft grey..light bluish green..repetition will make it less prominent. Blend.. you can theoretically go with very strong color that would balance it..but that's very bold and I'm not sure good for the space. but if was a small room..or room with very high ceilings..seal, deep purple..of course one needs to be into that too. THat's purely theoretical though...too big of a space, with standard ceilings.. you'll have to deal with ceilings too when picking a color that's strong and dark. Just thinking aloud.. -so much directions with furnishings..I can see ratttan. and velvet. and leather. and whatnot. you'll need to steer us a bit more..what stores do you like? any magazines/books/blogs you prefer? your favorite colors? anything you can tell us? do you like patterns? if yes which? can you shate inspirational pics? With art and lights and fabrics and a mix of surfaces..something reflective, something soft.. ..oh it can be a very cool place.

I don't care for area rugs of any kind. I like an uninterrupted vision on a floor. Just my preference. Plus if you have nice floors why cover them up. I did have 2 in my last house (that is were I found out I don't like them) , but they never creeped, slithered, wormed, lollygaged or crawled anywhere. They did fly though, out the front door when I found out I don't like area rugs. Find a nice pattern and enjoy. You might find out you like the W/W carpet in the basement if you live in a cold weather climate. The floor is so much warmer.