While many people might say that diamonds appear colourless or clear, most contain subtle tones of yellow and brown. Therefore the degree of colourlessness has an influence on its beauty and thus price. For example the completely colourless, icy white diamonds are extremely rare and are priced accordingly.
Diamond colours are graded according to letters of the alphabet, starting at D the exceptionally white and exceptionally rare, right the way through to the letter Z, the tinted yellowy/brown colour.
