Colour is the third of the 4 (or 5!) Cs and plays a key role in a diamond’s appearance, rarity, and value. The colour of the diamond refers to the presence (or absence) of colour in the stone.
For white diamonds, less colour means a higher grade. But not all colour is created equal—there’s a clear distinction between a near-colourless diamond and a fancy-coloured diamond like a vivid yellow or pink. I know, I know… it can get confusing.
White Diamond Colour Scale
Most diamonds are graded on a scale ranging from D (colourless) to Z (light yellow or brown):
- D–F (Colourless): The rarest and most valuable, these diamonds are completely free of colour to the naked eye and under magnification.
- G–J (Near Colourless): Slight traces of colour visible under magnification, but appear white to the naked eye. These offer excellent value without compromising beauty.
- K–M (Faint Colour): A noticeable yellow or brown tint becomes apparent, particularly in larger stones.
- N–Z (Noticeable Colour): Diamonds in this range have obvious yellow or brown tones visible to the naked eye.
However, when a diamond’s colour is rich and saturated enough, it is classified as a fancy-coloured diamond rather than being evaluated on the traditional D–Z scale.
These diamonds derive their value from the intensity and vibrancy of their colour, with shades like yellow, pink, and blue often becoming the centrepiece of some of the most remarkable jewellery.
While pale yellow diamonds within the Z range of the D–Z scale might be considered undesirable due to their faint hue, a diamond with a deeply saturated and uniform yellow tone is graded as a fancy yellow diamond, which is highly sought after. This difference lies in the way the colour is distributed and how intense it appears.
Fancy-coloured diamonds are graded on a unique scale ranging from Faint to Fancy Vivid, with the latter being the most striking and valuable.
What Causes Colour in Diamonds?
Not all colour in diamonds is created equal: it arises from various natural phenomena during their formation.
One of the primary causes is the presence of trace elements. For instance, nitrogen atoms within the diamond’s crystal structure are responsible for producing yellow hues, while boron imparts a rare and captivating blue tone, famously seen in iconic gems like the Hope Diamond.
Another factor is structural distortions that occur during the diamond’s growth, which can result in colours like the delicate pinks found in Argyle diamonds. And in addition, exposure to natural irradiation can cause shades of green to develop, adding another layer of intrigue to these beautiful coloured stones. These unique processes ensure that no two diamonds are ever exactly alike, making each one a singular treasure.
These colours have mostly just been seen in mined diamonds up to now, with extra processing used on lab diamonds after their formation to give them colour. However, lab diamond tech is moving fast, and there are more ‘natural’ additions added to craft the vivid colours we see in mined diamonds – created above-ground.
How Colour Affects Appearance
The absence of colour enhances a diamond’s brilliance, as it reflects white light more effectively. However, the choice of metal in a diamond’s setting can influence how its colour is perceived. Cooler metals, such as platinum or white gold, accentuate the purity of higher-grade diamonds in the D–G range, while warmer metals like yellow or rose gold complement the faint tones found in diamonds graded H–M. This interplay between setting and diamond creates an opportunity to customise your ring, allowing even faintly coloured stones to appear whiter and more vibrant.
One of our favourite ways to do this is with mixed metals within an engagement ring: you don’t know perfection until you’ve seen a D diamond paired with a gold band in a white gold setting… perfection.
One common misconception is that only colourless diamonds are beautiful, but this is far from the truth. Near-colourless diamonds, graded G–J, often appear indistinguishable from colourless ones to the naked eye and provide excellent value.
Another myth is that fancy-coloured diamonds are less valuable; in reality, stones with vivid and uniform hues, such as fancy yellows or pinks, are some of the rarest and most expensive gems on the market.
Colour Grading in Lab Grown vs. Mined Diamonds
Lab-grown and mined diamonds are graded using the same D–Z colour scale, but lab-grown stones often achieve higher colour grades due to their controlled growth environments. While both types can produce stunning colourless or fancy hues, lab-grown diamonds offer exceptional value, particularly in the near-colourless range, where their brilliance and purity shine.
We’re here to help you navigate the world of diamond colour: whether you’re drawn to the pristine elegance of a colourless diamond, or the bold beauty of a fancy hue, our collection has something for everyone.
Book a consultation today and find your perfect gem.