*waves my hand* I'm a clutterbug too! I am at my most creative amidst a certain amount of chaos, so a couple of you would feel right at home in my sewing room. Most of you would probably be horrified!
Mine are a light neutral tan; same color as most of the rest of the house. My sewing room is the living room and my house sort of just goes room to room without any clear indication where one stops and the other ends, so the entire downstairs space and up the stairwell is all the same tan color.
If I had a "private" room that I could paint any color, I'd do the walls in flat black. It sounds crazy but I've had that in a craft room before and I loved it! In a room with black walls I feel like I'm in a MASSIVE space; the walls just vanish. I am an insomniac so I'm often working in my room at odd late hours - during the day when the windows are lit the illusion is gone, but if the windows are dark, it's like I'm sitting in infinite space. I miss that room! I'd love to do that in our bedroom, DH is on the fence about it. I think I'm slowly winning.
People thought I was totally crazy, but most people who saw the room were surprised at how spacious it made the (very small) room feel. When I sold that house it wasn't too hard to paint over; just a quick layer of primer and the walls went back to white very easily.
I miss that room. My living room space is much larger, but I miss the privacy of my own little space.