Ummm. . .paint all the walls the same color. Accent walls were trendy in the 1990s. Now they just look dated.

Very True , and after a few days you start hating that wall , not very In .

If you wish a strong, matching accent, use something other than painting an entire wall. Add a bold but simple picture from floor to ceiling (allposters has great murals) so it doesn't take up the whole space but as a swath and accent the same color or shape, maybe turned sideways in the adjoining room. You can get some great shapes. I love the almost abstract shapes in Antelope Canyon pics. Or even something with waves or movement.

If you love the accent wall go for it. Trends come and go and come again, so just have what you love! People are now also using wallpaper for accent walls, or murals. They are just being re-vamped a bit but they are definitely not "out". I repeat, have what you love and don't worry about anyone else. You have to live there!
If you don't want to go for a bold contrast how about a deeper shade of the existing colour?
To choose the best wall for your accent, look at the one that most defines the living space, it's usually the one with the least doorways or windows in it. In your case it would probably be either the one behind the couch or the long unbroken wall in the living area?
Hope these tips help.

Thank u all for ur comments. I realy thought painting one wall another collor was something from this century. And because of all the pictures I saw on houzz and even more the advice u all gave to the people on houzz. Now I have some thinking to do...

I agree with not having an accent wall in your situation since there are isn't a defined wall surface for the accent color to begin and stop. Consider adding accent colors in your accessories, where they can be easily changed as you wish.

Here in Oz accent walls are back in fashion again! I think you can do a lot to a room with a big punch of color and after all, it's only paint. I would however paint the wall in front of the couch and the wall at the end of the dining area the same color. As Dytecture points out you can't really have an accent wall that finishes at a door way which rules out the wall behind the couch. I've got a similar room that no matter how much color I throw in with accessories just still seems to need a warm cheerful color on a couple of walls. To paint or not to paint, that is the question.

Thank u portpiro I like ur idea!

I olso like the idea of choosing the accents in accessories. This is just a layout of the hous I'm building. I hav't decided on collors yet. I was thinking maybe a light grey. Or some beige collor. Don't know. In the center of the kitchen there should be an island. And were the bureau stands I want a build in desk.

I recommend the 3D walls panels
There are different designs

I'm a bit confused now as to why most of u wonderful desingers tell me to put no accent wall. In other post u guys recommend accent walls. Can some one please explain to me why it's better to paint all the walls the same collor? And why u recommend no accent wall?

The large, painted, contrasting wall is out. If it's a must, try 2 shades darker of the same color, but not a large contrast. The accent walls are now wallpaper. Big, bold, beautiful wallpaper. It's not our mom's wallpaper! Good luck!