Because colour is so powerful we tend to look for rules for its use, but there are no hard and fast rules. How you use colour is a very individual and creative choice, but understanding how colour works will help you use it more effectively.
Properties of colour
Blues and greens can introduce a cool mood into a room. The level of coolness will depend on the intensity of the colours. Cool colours may also be used to change the appearance of a room, pushing back walls and furnishings and making the room appear more spacious. They look best in a room with a sunny exposure, where the colours counteract some of the strength of the direct sun. They should be avoided in shaded rooms. This makes them a good choice for small, narrow rooms that you want to seem more spacious
Such as red and orange, have an opposite effect, closing in the walls of a room. If the room is large, its dimensions seem decreased. Warm colours look their best in a not so bright room with southern light, so that the bright effect of the sunny colours is not too overbearing. They are therefore a good choice for large, uninviting rooms you want to make more intimate and welcoming.
Use the most intense hues and values in areas occupied for short periods of time, such as formal dining rooms, hallways, staff lunch rooms, laundries and entrances. Avoid monotony and treat the eye and psyche to at least a moderate variety. Visual stimulus or relief is vital. Harmonious colour selections are created by a pleasing relationship of the three dimensions of colour: hue, intensity and value.
Using correct proportions of colour ensures that your scheme will be aesthetically pleasing. A touch of contrasting colour may be lively and exciting but too much can become uncomfortable. On the other hand, too much moderation produces dullness. Personal taste and preferences are the most important considerations in choosing a colour scheme.
Finally, think about proportions of colours. A basic rule using two thirds one colour and one third another is always successful. Different colours affect the way we view a room. Use colour to create an illusion. Colour can highlight the good features of a room and camouflage defects.