For millions of years, the human race has associated certain colours with specific emotions or feelings. For example, purple is commonly associated with royalty and the rich, as in the past the dyes were very expensive. White has long been regarded as the colour of purity, hence it is the most common colour of choice for brides.
When choosing the colour scheme of your room, consider the feeling you wish to portray. If you want to give a warm, comfortable feeling, you should select red, orange and light brown hues. These colours are typically classified in the 'earth' category, named as they reflect naturally occurring, earthy colours. The reason we feel so relaxed in a room with these 'warm' colours is that brighter colours encourage the brain to keep alert - hence we never feel totally relaxed in bright rooms. Warmer colours encourage the brain to relax, and prevent over-stimulation.
Naturally, warm colours are not for everybody. There is a huge range of colours available, and most of these can bring about a number of feelings, which can represent a number of different aspects of our lives. Red, for example, is supposed to be a stimulant, and is supposed to be ideal for kitchens. Red paint mixed with a black trim can not only be stimulating to the mind, but can also give a pleasant retro style to your room. In addition to use in kitchens, red can give a particularly regal look to bedrooms. However, most interior designers and decorators will not use red unless specifically requested to. Many don't like a red hue, and prefer to go for a darker, burgundy hue instead, as it is not quite as visually stimulating, yet still conveys the same visual effect.
If you are more interested in a bright and cheerful room, lighter colours such as yellow and orange will be ideal. Lighter tones allow a lighter, more cheerful tone to the room, with yellow colours typically signifying happiness and sunshine. Orange hues are also a nice choice, as they are considered to be friendly and informal.
If a calming tone is what you want, blues and greens are a popular selection, as they are largely associated with nature - calm blue seas, grassy meadows and a clear sky.
Before choosing a specific colour scheme, bear in mind the room's use, as the colours you select will set the tone of the room.