Monochromatic Colour schemes use tones of the same colour. The use of monochromatic colours makes a room seem larger. You can achieve interesting effects by using different values (i.e. light and dark) and intensities of a colour.
Analogous Colour schemes use two or three colours adjacent to each other on the colour wheel. The use of analogous colours creates a flow of colours that blend together to produce a subtle and interesting effect.
Triadic Colour schemes as the name implies, are based on three colours, equal distances from each other on the colour wheel. The best example of this is the three primaries, red, blue and yellow. Using a triad colour scheme is a little more tricky, but produces very dramatic results. It is best to choose one as the predominant colour (i.e. blue walls with red and yellow accents).
Complementary Colour schemes use colours which lie directly opposite each other on the colour wheel and are as unlike one another as they can be (i.e. burgundy and green). One colour is generally more dominant.
Accented Neutral Colour schemes use neutral colours (greys, beiges or whites) as main colour and then add a punch with a dark accent colour to add visual interest (i.e. a cream room accented with black).