Your seating arrangement does not seem right. Your sectional seems so far from the TV, or is it the picture. You'd want to create a seating arrangement around your focal point(TV).

Here are a few I've seen available in Houzz Marketplace...

Kas Allure 4062 Blue Green Artisan Rug, 5 Ft X 7 Ft · More Info

Surya Lighthouse LTH-7030 Rug 5'x8' Pacific Blue, Malachite Green Rug · More Info

Surya Plush Noble Green-Blue 5'x8' Rectangle Area Rug · More Info

Sphinx Kaleidoscope Grey and Blue and Green Rug - 504D5, 5' 3"x7' 6" · More Info

Typically, painting the walls should come first to make matching a little easier, but for colors that can match a seafoam/aqua, you could try a soft yellow or harmonize it with neutral colors. You can also add some pink in the mix too.

Metallic furnishings will also be a great accent for this specific color as well.

Hope this helps out!

If that is the only place the television can be then the sofa should be moved much closer to it. I would forget the rug until you have the furniture better arranged.

Lisa, you are right. It is much easier to match paint to your rug as a rug is a much larger purchase than a can of paint. Find a rug you love then move on from there.

I'd consider a darker color, more taupe than just a gray, for the walls. I think it will make the sofa color richer. Try BM revolutionary storm.

Sphinx Kaleidoscope Grey and Blue and Green Rug - 504D5, 5' 3"x7' 6" · More Info

Jaipur Fables Tria Beige FB61 9'x12' Area Rug · More Info

Yep, totally agree @LisaWilliams. Finding a rug you like — color, size, texture and personality — can be a challenge. Starting with a piece you love will make it easier later on AND can provide a cohesive starting point for inspiration.

If you want to use the rugs to create cohesion among colors/textures, I recommend using more than one in the space — that way you create a consistent look without being too matchy matchy. Given the size of your space, I think you can go pretty big with the rug, at least an 8x10 in the sofa area, and a smaller piece under or next to the dining area.

Another thing to keep in mind when looking to a hang a rug (which is amazing for a headboard effect or to add warmth/sound proofing in a room), you want to pick one that's not too heavy. Kilims or dhurries, which are flatweave rugs, are your best bets for hanging more easily without damaging the rug or the wall.

Hope this helps!

Kelly, paint comes last. Your instincts were correct in choosing the rug first. But before you choose a rug, you have to get your seating arrangement right because that will determine the size you need.

Looking at the third photo in your original post, I would say pull the sofa out of the corner so that the chaise leg of the sofa is centered on its wall, and the long leg of the sofa is centered between the windows. I'd also try the chair on the end of the sofa if there's room, either facing the chaise or angled toward the TV.

It's really hard to tell on a monitor, but also in that third photo and the fourth, the walls seem to have a pink undertone that's fighting fiercely with the curtains. Not to worry about it now, but something to keep in mind when you choose your paint.

I like this coastal vibe you've started here. You've made some nice choices so far.

How about moving the seating and giving us another photo?

Move the sofa to about here. Depending on how much space is left behind it, we might do a sofa table, or just big art.

Here are three rugs, one about the color of the curtains, one a deep teal-y green, and a brown zebra:

With some big art:

I agree with grover on moving the sofa more into the room. I like the 2nd rug suggestion also made by grover but I think the paintings should be hung somewhat higher. Paint is last. Rug is first, but after the furnishings are arranged the best way.

Sanddollars By The Sea Area Rug, Rectangle, Blue, 3'x5' · More Info

This of course would need to be larger.

Sofa table, couple of antique silver lamps and a silver bowl, art. Don't forget the art. And the Eileen Gray C-table for the chaise.