Colour is a significant factor in determining the quality of a diamond. A diamond’s colour grade refers to its lack of colour; diamonds commonly referred to as white are those diamonds that exhibit no colour. Most diamonds show faint tints of colour and the more obvious these tints are the less valuable the diamond. Fancy coloured diamonds are those of distinct colour. They are extremely rare and valuable. These diamonds range in colour from intense yellow to orange, blue, green, purple, pink and red.