Diamonds naturally range in colour from colourless to light yellow.

Diamond Colour Grade Scale

Image credit: GIA

Although diamonds are composed almost entirely of carbon, they do contain traces of other elements that create body colours in shades of yellow, grey, and brown.

Colourless diamonds that have low or no traces of colour are rarer and are, therefore, more valuable in general. However, note that this does not apply to fancy colour diamonds, which are not on the D to Z colour scale and are often extremely rare.

Diamonds on are graded using the Gemological Institute of America (GIA) classifications, using letters from D to Z — with D being colourless.

Colour grades are determined by comparing, under controlled conditions, a specific diamond to a set of standard "master" diamonds.

Diamond Colour Grade Chart:

Colour Grades



D, E, F

D to F Diamond Colour


It is only by direct comparison to colour master diamonds that a slight variation in colour can be detected between these three grades. To the untrained eye, D to F diamonds will look the same once mounted in jewellery.

G, H, I, JG to J Diamond Colour

Near Colourless

If the diamond is well cut, diamonds in this range will face up very well and only a slight tint of colour will be noticeable. This is a very popular range of colours in the New Zealand market as it allows a good balance between size and budget.

K, L, MK to M Diamond Colour

Faint Yellow

Again, these diamonds — if well cut — will face up well in jewellery, but the colour will be noticeable to the untrained eye. This may allow you to purchase a larger diamond if your budget is limited.

N to ZN to Z Diamond Colour

Very Light and Light Yellow

Diamonds in the N to Z colour grade range generally show a noticeable yellow, brown, or grey colour, and are considerably less valuable than diamonds in the D to M range. There is low demand for diamonds of these colour grades in the New Zealand market.

Next 4C: Clarity