Colour – or lack thereof – is commonly considered the second most significant quality among the four Cs – cut, colour, carat and clarity – when buying a diamond. Diamonds vary in colour from colourless to light yellow, with the least colour being the most rare and sought-after
Grade D diamonds are the rarest and highest quality attainable, emitting unsurpassed brilliance.E (colourless)
Grade E diamonds are extremely unusual, containing just a trace of color and providing exceptional brilliance.F (colourless)
Grade F diamonds are of superior quality, with minute traces of colour detectable by only a trained gemmologist.
Grades G and H diamonds appear colorless to all but a trained gemologist but do contain noticeable colour when compared to diamonds of a higher grade.I, J (Near Colourless)
Grades I and J diamonds are an exceptional value, containing slightly detectable colour.K, L, M (Near Colourless)
Grades K, L and M diamonds have a slightly noticeable color to both the untrained and trained eye, but remain striking and emit a wondrous fire.
To identify diamond colour, an industry standard grading system has been developed beginning with grade D, the highest colour quality denoting a total absence of colour, and ending with grades N through Z, the lowest colour quality denoting noticeable colour.
Transparent grade D diamonds have no chemical impurities or defects. Diamonds graded D through F have no noticeable colour, range from exceptional to rare white and are considered the strongest choice for their absolute brilliance and purity. The higher the diamond grade, the greater its light performance and price.
A diamond's colour grade affects its price, but it isn't the most important diamond characteristic to consider before purchasing a diamond.
Shoppers seeking value with a slightly lower quality grade, though still near-colourless to the untrained eye, can opt for grade G through H diamonds, which range from rare white to slightly tinted white. However diamonds graded K or beyond are extremely low quality stones and are, thus, typically not offered by premium jewellers. In fact, the lowest grade, Z, appears light yellow or even brown in colour.
An experienced jeweler or gemmologist will help you evaluate and select the best diamond for your needs.