Don't be afraid of colour and be sure to use colour with depth. For instance, it is important to remember that you can't necessarily make a dark and dingy room light by using pale colours. You will just make it duller. in fact, it's better to forget about that quest for a light room. Far better to opt for strong, dark, jewel-like colours that make it vibrant. Making a dark room darker will create a feeling of comfort, warmth and richness.
Conversely, if you have a room with large windows that is flooded with natural light, make it lighter. Remember, too, light rooms can drain colour so in these circumstance it is far better to use paler, cooler colours. The results will be both astonishing and a delight. A rich range of decorative effects can be achieved without using any colour at all - off-white decorating is the perfect foil in rooms that look out onto terraces and gardens. The effects of daylight and artificial light on a room are very different, and how your room appears at different times of the day needs careful study before you choose your colour scheme.
You can use colour inexpensively yet to advantage in, say, a dining-room. Change the look using different slip covers on the chairs and by your choice of china, glass and candles. Similarly, introduce changes of colour in a bathroom with towels or in a bedroom with bed linen. To reflect the changing seasons and completely alter the feel of a room, you can put pale cotton loose covers over rich velvet or tartan upholstery. Your room needs to be brighter in winter than in summer, and during the day far more than at night. You can carry out such colour experiments for a surprisingly modest cost.
Over-zealous colour matching can often prove an expensive mistake. You need to step-back, even leave the room from time to time, and consider the overall scheme. Then choose something slightly 'off' the main colour you had in your mind. It is likely to prove more relaxed, less contrived and easier to live with.