When I made the move from rentals to my own home that I could paint what ever color I wanted I was clueless on what to do. My best friend went with me and had some scissors and she cut out the floor plan of my home in the colors that we thought would look good. It turned out great!

I painted my dining room a deep scarlet color. I think it was called Claret from Benjamin Moore. It was really warm and inviting. We had a chair rail that we painted white to set off the dark red. We also painted the inside of the built in corner china cabinet a lighter shade of the color. And, we painted the ceiling white ... and had the wood floors stained a "white" color, so all together the white and other accents set off the darker color. It was gorgeous!

Don't be afraid to experiment with color, even dark colors. They look really rich. What will make the room look smaller is large furniture pieces, so if the room is small try to keep the size of the furnishings in mind.

Dark colors would definately make the space feel a little smaller. You might try picking two or three shades of the color you'd like and use them on different walls. That way perhaps only one wall is the darkest color. Maybe it's your "focus" area where pictures are and things like that.