The colour of a diamond is rated on an alphabetic scale from D to Z.
Colours D,E and F are described as colourless. These are very rare and due to limited supply would demand premium prices.
Diamonds graded as G/H, I/J fall into the “near colourless” group, with G/H being described as rare white diamonds. Colours I and J begin to show a subtle warmer tone, and are therefore more moderately priced.
Faint yellow diamonds are graded between K and M and would be more desirable than stones with more obvious yellow tendency which are in lesser demand.