Colour in most siutations needs to be thought about carefully. Colour is used for 3 main purposes.
1. Overall theme - Colour is used in a dominant way to create an emotional impact of a room.
Happy = yellow, chilled = ice green, dramatic = black, calm = blue, reflective = purple. So paint a wall or all of them in colours that create the emotional effect you are looking for. Then furnish with mostly neutral colours to support the main colour.
2. Highlights and Textures - Colours is used to create an expereince in the room. So colours are used in in curtains, furnishings and furniture uphostery and styles. Texture of fabrics and patterns in the highlights has the person interact in the room rather than set the emotional tone.
3. Splash - colour is used to focus people to something important. For example, in the picutre above, the deep red cushion calls you to see it first - drawing you into the place to sit. The red on the ottoman, subtly direct you to place something on it. All the other colours are complimentary to the main splash.
Whats the emotional theme of your room, how do you want to highlight it and how can you splash for maximum impact?