A diamond’s colour is one of the most noticeable of the 4Cs of diamond grading. Together with clarity, cut and carat weight, the colour is an indication of a diamond’s quality. Read our guide to understanding diamond colour grades, complete with a diamond colour chart, so you can choose the perfect diamond for your engagement ring, pair of earrings, or other item of jewellery. Browse our selection of IGI, HRD and GIA certified diamonds with excellent colour grades.

Diamonds predominantly occur as colourless to yellow, although other ‘fancy coloured diamonds’ can be found. The vast majority of diamonds are coloured by the presence of nitrogen within the crystal structure. The quantity of nitrogen atoms, and the way in which they are grouped can affect the diamond’s body colour. The most highly valued diamond on the GIA colourless to yellow scale is a D, completely colourless seen face up and face down. All other factors being equal, a diamond with a higher colour grading will be worth more than a diamond with a low colour grading.

Diamond graders assess loose diamonds for their colour grade. This is because a diamond’s setting can distort the perceived colour of the stone. A yellow or rose gold mount can reflect flashes or yellow or orange colour into the stone. Therefore, colour can only accurately be graded if the stone is loose.

A diamond light box is used to illuminate the diamond. These light boxes provide a source of light that is free from ultraviolet light that can also distort the apparent colour of the diamond. Diamonds are assessed side on, by looking through the pavilion facets through to the table of the stone. The diamond is viewed on a white tray or card to best assess any saturation of colour.

An accurate colour grade is achieved by comparing the diamond to a set of pre-graded ‘master stones’ for consistent comparison colour grading. The chart below describes the GIA criteria for colour grading loose diamonds. It is worth bearing in mind that each colour grade represents a range of colour, not just one point along the series. Diamond colour grading takes years of experience, with slight nuances of colour that can be imperceptible to the untrained eye. Therefore a certificated stone from a reputable laboratory is your guarantee of a diamond’s quality. ?




Face up colourless, face down colourless.


Face up colourless, face down colourless.


Face up colourless, face down colourless.


Face up colourless, face down colourless.


Face up colourless, face down slightly tinted.


Face up colourless, face down slightly tinted.


Face up colourless, face down slightly tinted.


Face up slightly tinted, face down obviously tinted.


Face up slightly tinted, face down obviously tinted.

M – Z

Face up obviously tinted, face down obviously tinted.


Face up obvious colour.


For a colourless appearance to your diamond, we would recommend opting for a diamond colour grading of H or above. If you desire a warm hue to the diamond without a very noticeable yellow tint, I to K grades are also acceptable. However, colour is perhaps one of the most subjective factors of diamond grading, and it is largely down to personal preference what diamond colour grading works best for your skin tone, jewellery design, or accent gemstones in the setting.

Contact our team of diamond experts and fine jewellery specialists who with many years of combined experience are on hand to assist with helping you source and select the perfect diamond. Call us on?01335 453 453 or email