The diamond colour grading scale varies from totally colourless to light yellow. The differences between one diamond colour grade and another are very subtle and difficult to distinguish.

Because a colourless diamond, like a glass pane, allows more light to pass through it than a coloured diamond, colourless diamonds emit more sparkle and fire. The formation process of a diamond ensures that only a few, rare diamonds are truly colourless so the whiter a diamond's colour, the greater its value.

Fancy colour diamonds do not follow this rule. These diamonds, which are extremely rare and very expensive, can be any colour from blue to green to bright yellow. These are actually more valuable because of their colour. Some of the most sort after diamonds of today, thanks to celebrities such as Victoria Beckham and Jennifer Lopez, are the fancy colours such as Pink, Blue, Yellow, Green, Champagne & Fancy Cognac. These fancy colour diamonds come in varying depth of colour ranging from intense to very, very light. As a rule the more intense the colour the higher the value.

D-F : Colourless: perfect or almost perfect colour.

G-J : Near colourless: good to very good colour, and this diamond may appear colourless when mounted, especially in white gold or platinum. Shows virtually no colour that is visible to the untrained eye.

K-M : Light but noticeable yellow or brown tint. Not recommended for larger diamond stone purchases, especially in engagement rings. The colour in diamonds graded K-Z can detract from the beauty of a diamond. It's especially noticeable set in platinum or white gold.

Colour is important to consider if buying a diamond that is going to sit next to another diamond. It would be important to colour match the diamonds. If the colour varies severely diamonds may appear more yellow if worn together than if worn apart.