What is the room used for?
Bedrooms should feel tranquil. When you walk into a bedroom you want to instantly feel calmer. So choose a colour which, when you look at it, you can feel yourself relaxing. For many people cool tones such as blues or blue/greys have this effect. Think of the sky and the sea. Other people prefer warmer colours, so neutral tones with a slight red base such as Farrow & Ball's Dimity, can create a feeling of warmth and cosiness. For a bolder look, darker colours on the walls, and perhaps ceiling, can create a feeling of being safe, secure and enclosed.