You don't have to always change the Color
Sometimes you just need a fresh coat of paint, and not a new color. If you love the colors in a room, but the room just looks dingy no matter how much cleaning you do, and there are dings in the trim, and a bunch of holes where pictures used to hang, you might just want to consider putting a fresh coat of the same color on the walls and trim. I recently did a repaint of a great room in the original color on the walls, and put a white on the trim that was a bit brighter than the original color. Even though the walls were the same color the fresh coat (along with repairing all of the holes and other imperfections) made a huge difference. I also did the hallways and entrance, which were changed to a light grey. The colors used were C2's Architectural White on all of the trim (however it was mixed using Benjamin Moore's Advance Satin) C2's Linger in LOVO eggshell, and American White on the walls in the hallways and stairwell in Benjamin Moore's Regal Select eggshell.