My husband's orange sixties-design armchair was my first inspiration in this room.To highlight it, I made a warm/cold contrast with the grey-blue wall.
Colors used in my room:
Grey, blue, orange, red, yellow and white.
Tips for using color successfully:
Small touches of colors on a white or grey neutral background. Warm/cold contrast is a good solution too. You also have to think about light, it's the most important thing to create a cozy and warm atmosphere.