I wouldn't mind an accent wall either

Take a look at these inspiration pics (hover to expand photos and click on the name for design details)




Hilltop House paint is custom, closest to it is a Ralph Lauren paint color: Tudric Pewter RL Number: RLTH239

For your wall color you can't go wrong with either BM Edgecomb Gray or BM Revere Pewter. The accent wall depends upon what you want to feature. For a beautiful space like yours, you might want to feature huge modern artwork rather than break it up with an accent wall.

Art is personal: here is a search link for modern art for you http://www.etsy.com/browse/art/painting/abstract?h=d7e5d9bf&lid=162902355&ref=cat_subcat_tile_8

Hmmm a grey on grey does look good

The Ritz-Carlton image is nice in that it shows a dark sofa with darker walls however that space has lighter floors and a lot of great natural light.

If you're going to go neutral definitely complement this sofa with a lighter grey wall but since your floors are dark you may want to consider buying the sofa in a lighter color as well.

An orange accent wall would also complement this sofa since it's a cool grey with blue hues. A bright accent wall could also bring some energy to a room with mostly light grey walls.
Consider adding an accent wall in s-g-240 "Dragon Fire" by Behr http://www.behr.com/consumer/colors/paint#

Or Ralph Lauren's "Bold Orange" RLIB229 http://www.ralphlaurenhome.com/products/paint/Lifestyle_Colors/items.aspx?haid=83

@Denita i did use the grey on grey concept.. this is what i did with it.... it was a DIY project