The mesmerising sparkle of a natural diamond often steals the spotlight, but there’s so much to admire — and learn — about its colour.
Like size and shape, diamond colour is broad, spanning the full rainbow spectrum. Just look at Scarlett Johansson’s spectacular engagement ring from Colin Jost — an 11-carat, toffee-coloured Desert diamond on a distinctive brown band1.
Unconventional? Sure. Unforgettable? No question. The ring that Ryan Reynolds proposed to Blake Lively with also stood out for its oval slightly pink (and so very stunning!) diamond.
What colour are diamonds, really? What you may not have known is that they can range from vivid reds to golden champagnes and sky blues. Natural diamond colour isn’t just about visual appeal — or, as many often presume, some kind of man-made trickery. The shades of different types of diamonds are the result of a billion-year alchemy beneath the Earth’s surface, giving each gem a distinctive hue that’s a true geological one-off2.
In the jewellery world, colour can directly affect a diamond’s grade and price3. Colour is one of the 4Cs of diamonds (alongside cut, clarity and carat weight), which help to determine a diamond’s overall value and quality4, so doing your homework on the topic is no bad thing if you’re interested in buying natural diamonds.
The science behind diamond colour formation
Natural diamonds form deep within the Earth, typically about 140 to 200 kilometres beneath its surface, over the course of one to three billion years5. Under intense heat and pressure, carbon atoms bond in a crystalline structure to form diamonds. But it’s not just carbon that gets caught up in the process — the introduction of trace elements is what gives diamonds their colours.
Nitrogen is the most common trace element and gives diamonds a yellow or brown hue6, like the iconic 128.54-carat yellow Tiffany Diamond most famously worn by Audrey Hepburn while promoting Breakfast at Tiffany’s.
Boron typically creates blue gemstones7, such as the mesmerising Laguna Blu Diamond that Priyanka Chopra Jonas wore around her neck to the 2023 Met Gala8.
Another fantastic coloured diamond that has, over the decades, earned itself an air of mystery, thanks to its legacy of being cursed, is the exquisite Hope Diamond. A riveting greyish blue in colour, it’s one of the most fabled Golconda diamonds because… who doesn’t like a story about spectacular jewels and curses?
Irregularities and distortions in the structure (also called crystal lattice) of a diamond can scatter light in ways that produce shades of pink or red. Vivid green colours in diamonds is often caused by natural radiation9. Fun fact: the Dresden Green, another exquisite Golconda diamond, is considered the largest and finest green diamond ever recorded!
Because each natural diamond forms under slightly different conditions (even when formed in the same geographic location), no two will exhibit colour in exactly the same way.
Colour in diamonds doesn’t mean imperfection, let’s be clear about that! Colour, in fact, is what makes some diamonds incredibly rare — only one in 10,000 carats shows fancy colour10. And for gems with super rich, intense hues, you’re looking at odds closer to one in 25,00011.
Understanding the diamond colour scale
On the D-to-Z diamond colour scale12, which applies to white or colourless diamonds, D is the highest grade, given to completely colourless gems, and Z is the lowest grade, given to those showing a light yellow or brown tint. The closer a diamond is to D, the rarer and more expensive it is13.
The diamond colour scale helps standardise grading, but within each grade exists a world of subtle variation, and, of course, what you lean towards is a personal choice. Some people look for the best diamond colour grade according to the scale (D or E), opting for a gem that’s strikingly bright white.
Others prefer warmer, Desert diamond tones (G to M), picking diamonds that are cream, honey and champagne in colour. These can feel more mellow, romantic or vintage in their look. Warmer-toned diamonds, those graded G to J, are also excellent complements for rose gold and yellow gold.
Fancy coloured diamonds and their value
Coloured diamond jewellery isn’t just stunning to look at (picture a breathtaking polki necklace that pairs the timeless gleam of gold with yellow diamonds!); the rare gemstones remind us how truly miraculous Mother Nature can be.
What determines their value?
Fancy colour (or fancy coloured) diamonds14, which fall outside the D-to-Z scale, are considered the most prized. Graded using a separate classification system, fancy colour diamonds come in shades of pink, blue, green, red, yellow and brown.
And while rarity plays a significant role, the value of fancy colour diamonds is ultimately determined by a combination of factors like its shade, saturation, size and market demand.
Which coloured diamonds are the most expensive?
What’s the most valuable colour? Among the rare diamond colours, red diamonds are typically the least common, but it’s vivid blues that often top sales charts in terms of price per carat, followed closely by pinks15.
What sort of bids do fancy coloured diamonds fetch at auction? Big ones.
The 5.11-carat Moussaieff Red sold for $8 million in 200116, while, in 2016, the 14.62-carat Oppenheimer Blue fetched $57.5 million at Christie’s17, and the 59.60-carat Pink Star brought in a record-breaking $71.2 million at Sotheby’s in 201718.
Lab-grown vs natural diamonds: Do they differ in colour?
Lab-grown stones (or LGDs) are created in factories using High Pressure High Temperature (HPHT) or Chemical Vapor Deposition (CVD) methods, over a few weeks19.
Because the process happens quickly in a highly controlled setting, the results tend to be consistent (you can predict what they’ll look like before they’ve been made). LGD batches often have similar colour, clarity and structure, with less variation from one to the next.
And yes, they can be produced in specific colours like pink, blue or yellow, for example, by adding trace elements or using post-growth treatments20.
But unlike natural diamonds, whose colour is shaped over billions of years and therefore serves as a stamp of authenticity and uniqueness, lab-grown colour lacks the one-of-a-kind character and irresistible allure that nature spectacularly creates all by itself. Sometime shades of synthetic diamonds can look fake, neon or oversaturated.
In terms of emotional value, coloured natural diamonds trump LGDs that are synthetically coloured — while the former tells the unique stories of the gemstones, LGDs only reflect the power of synthetic production in highly-controlled man-made settings.
How to choose the right diamond colour?
Deciding on the best diamond colour for you isn’t about choosing the most valuable or following trends. It’s about finding a shade that complements your individual style, complexion and feels authentic to you.
Some helpful pointers for picking a colour are…
- The surrounding metal and lighting can dramatically affect how a diamond appears. Cooler tones in the D–F range, for example, look most striking set in white gold or platinum. Warmer hues from G to J are brought out beautifully by yellow or rose gold settings21.
- Skin tone also plays a role: warmer diamond colours are known to particularly complement olive or deeper skin tones, while cooler gems are more likely to pop against fairer complexions22.
- What a diamond is paired with also plays a part, as diamond facets (its flat surfaces) act like tiny mirrors. A diamond with subtle warmth may appear more colourless surrounded by bright accent stones that reflect white light23.
- Considering the occasion and your outfits will also help steer you in the right direction.
Whatever colour you end up leaning towards, have fun finding it and making a statement with it. And who says you must be limited to just one — rainbow jewellery collection, anyone?
Sources:
- Instyle.com, Celebrity coloured stone engagement rings ↩︎
- Gemsociety.org, Most expensive diamond colours ↩︎
- Gia.edu, Diamond quality factor ↩︎
- Gia.edu, The 4Cs: colour ↩︎
- Cape Town Diamond Museum, Formation of diamonds ↩︎
- Gia.edu, Naturally coloured yellow and orange diamonds ↩︎
- Qz.com, Why are blue diamonds blue ↩︎
- Vogue.co.uk, Priyanka Chopra Jonas’ blue diamond necklace at the Met Gala 2023 ↩︎
- Gia.edu/doc/GG-SP18-Breeding.pdf ↩︎
- Gia.edu, The magic of coloured diamonds ↩︎
- Gia.edu, The magic of coloured diamonds ↩︎
- Gia.edu, The 4Cs: colour ↩︎
- Diamonds.pro, D colour grade diamonds ↩︎
- Gemsociety.org, Most expensive diamond colours ↩︎
- Gemsociety.org, Most expensive diamond colours ↩︎
- Cape Town Diamond Museum, Facts about red diamonds ↩︎
- Forbes.com, Oppenheimer blue diamond sells for world auction record ↩︎
- Naturaldiamonds.com, Pink Star diamond ↩︎
- Gemsociety.org, Lab-grown diamond production methods ↩︎
- Diamonds.pro, Lab-created pink diamonds ↩︎
- Gia.edu, Engagement ring setting metals ↩︎
- Skinbeautybar.com, The-best diamond colours for your skin tone ↩︎
- Gia.edu, Diamond colour: seven things you need to know ↩︎
