So I’m starting to bring together some new furniture for my place. My goal here is to go with Grays, blues, a pop of yellow/green and natural wood for things like the floating entertainment center/coffee table, etc. At the moment, i just placed an order for this sofa, in Marlow Dolphin
http://www.truemodern.com/shop/furniture/grown-up/jackson-114-sofa-with-chaise.html

Next I want to add an area rug. My issue here is I am prone to buying things based on how I think it would look in my head, but when I actually get this in place, it’s a whole different story. So before I run off and drop some hard earned cash on a nice rug I was looking to see what kind of advice i could get.

The pops of yellow/green (still undecided) will come from throw pillows, small decor on the tables, and maybe on the area rug. But I'm not sure what color to go with for the rug itself. At first I was thinking blues/grays, but wasn't sure how to mix this up as far as what color would dominate the overall rug. I measured the area and for the most part, a 9'x9' rug would come right up to the sofa and then span over to the foot of the media center.

When looking at the pictures, the sofa will butt up against the large windows, on the opposite wall of course the media center.

Any ideas are appreciated!