The most sought after colour for a diamond is one where no colour is evident because it is the totally colourless diamond that acts as a prism allowing light to pass effortlessly through to be transformed into a rainbow of colours. Whilist the majority of gem diamonds appear to be colourless, others can contain icreasing shades of yellow to brown, some of which are referred to as champagne diamonds. Other diamonds of exceptional colour, red, blue, pink and amber are known as "Fancies".
The colour grading scale varies from totally colourless to light colour or tinted. The differences between one grade and another are very subtle as can be seen by the number of grades within any one category.