Colour Grading
White colored, or colourless, diamonds are categorised into the following: Colourless, Nearly colourless, Faintly tinted (usually yellow), Lightly tinted (usually yellow) and Tinted (usually yellow but may progress to brownish).
The scale and grading for colourless diamonds goes from ‘D’ (colourless) to ‘Z’ (dark yellow). The less colour, the more expensive.