Diamond Colour Scale
The GIA grades all diamond colours using a scale from D (colourless) to Z (slightly coloured). Find out which colour grades to choose and which to avoid, with the aid of a diamond colour grade chart and information from expert gemmologists.
What is diamond colour?
As one of the fundamental 4Cs of diamond quality, colour plays a major role in both the beauty and the value of your diamond engagement ring.
In a perfect world, a technically colourless diamond is completely clear of any trace colour and is tint-free. In reality, a large portion of natural diamonds contain subtle traces of yellow or brown that can softly affect their appearance. The closer a diamond comes to being entirely colourless, the rarer and more highly graded it will be.
To keep standards uniform across the jewellery industry, experts evaluate diamonds under precise lighting against a 'master set' of pre-graded stones, assigning a letter grade from D to Z. The scale starts at D (completely colourless and icy-white) and goes down to Z (showing a noticeable light yellow or brown tint). Diamonds graded D-F are considered to be within the ‘colourless zone’.
White vs fancy coloured diamonds
The standard D–Z scale applies only to traditional colourless diamonds, that means any diamond that isn’t considered a ‘fancy colour’. Fancy colour diamonds are any stones that naturally form with intense, vibrant hues – such as pink, blue, or vivid yellow – fall completely outside this spectrum. These are classified on an entirely separate scale for the strength and richness of their colour, rather than their absence.
Why does diamond colour matter?
Diamond colour matters because it directly impacts two things: the visual tone of your ring and your overall budget. While a diamond’s cut is responsible for its sparkle, its colour grade determines whether the stone looks crisp and icy or soft and warm to the naked eye.
Because completely colourless stones are exceptionally rare, they command a massive premium. However, because colour is highly subjective and heavily influenced by outside factors, understanding how it behaves is the ultimate way to maximise your budget. By choosing wisely, you can often save money without sacrificing any of the ring's visual beauty.
Diamond colour chart
To help you visualise these differences, the jewellery world relies on the GIA’s universal D to Z grading scale. When looking at the chart below, you’ll notice that the shifts between individual letter grades are incredibly subtle.
Whilst premium D to F diamonds are completely colourless, stones in the G to H range still appear relatively bright and colourless to the naked eye once set into a ring, although you may notice a slight warmth to the stone. It is only as you move further down into the I to J bracket and beyond that a noticeable tint begins to emerge, gradually deepening in intensity all the way down to Z. This tint can be yellow, green, brown or even grey-ish.
The GIA colour scale and breakdown
| Colour group | GIA grades | What it looks like in real life | Rarity and value status |
|---|---|---|---|
| Colourless | D, E, F | Completely clear with zero detectable tint. Displays a perfectly crisp, icy-white look. | Premium tier. These are exceptionally rare and command the highest price points due to their absolute purity. |
| Near-Colourless | G, H, I, J | Appears face-up white, and clean to the naked eye. Any subtle warmth is typically only visible to an expert under strict laboratory lighting. | The value sweet spot. These grades offer the look of a premium white diamond without the top-tier price tag. |
| Faint Colour | K, L, M | A faint, warm yellow or soft brownish tint can be seen by the untrained eye, especially in larger diamonds. | Budget-friendly. While accessible, the visible tint can slightly reduce the stone's perceived brightness. |
| Very Light to Light | N – Z | A clear, highly noticeable yellow or warm hue is visible across almost all lighting conditions. | Commercial grade. These stones sit on the boundary of fancy coloured diamonds and are rarely used in traditional engagement rings. |
We get it, you’ve never done this before.
That’s why we have diamond and design experts on hand, who are here to guide you through every step – from understanding what carat, colour, cut and clarity mean, to designing the perfect ring.
What is the best colour for a diamond?
| Setting / category | Recommended grades | Why it works |
|---|---|---|
| Best overall | D, E, or F (colourless) | The purest, brightest white a diamond can offer. These top grades look crisp and icy in any setting, and they hold their brilliance beautifully against platinum and white gold, where any hint of warmth would otherwise show. |
| Best compromise | G or H (near-colourless) | A sensible option if you're choosing a yellow gold setting, which naturally softens any faint warmth in the stone, or if you're working to a very tight budget. Bear in mind the price difference compared to D–F is often smaller than you might expect. |
| Best to avoid for a colourless look | I and below | From I onwards, a warm tint becomes more noticeable to the naked eye. If an icy-white diamond is the goal, we'd recommend staying at H or above. |
| Best for a warm tone | G to K | Perfect if you love a softer, vintage-inspired glow. These grades pair especially well with yellow and rose gold, complementing the warmth of the metal for a cohesive, romantic finish. |
A diamond’s colour grade is one of the most visible and apparent grades of all. A poor colour grade will be noticeable to the naked eye (unlike, for example, clarity grade, which requires magnification).
If you are choosing a yellow gold or rose gold setting, our gemmologists advise sticking to D, E or F colour diamonds. Platinum will contrast against and highlight any yellow tints in lower colour grades, so a colourless stone is highly recommended.
For a yellow gold or rose gold ring, you may want to lower the diamond grade to G or H to match the warmth of the metal, but most people stick with D-F. Yellow gold metal will reflect a little into the diamond, so by picking a top colour grade, you help counteract this issue. You can also choose platinum claws for your yellow gold ring, to keep the diamond looking bright and icy.
The causes of diamond colour
A poor diamond colour grade will appear slightly yellow, brown or even greenish in tone. This is because trace elements can be found within the pure carbon diamond, which encourages the presence of colour. Yellow and brown tints are caused by traces of nitrogen. The stronger the colour, the greater the presence of nitrogen.
Some fancy coloured diamonds also contain trace elements that cause their colour, like boron in blue diamonds. Some, like pink diamonds, are coloured due to the crystal structure, which in this case absorbs most colours in the spectral range, emitting a red-pink light. Green diamonds pick up their colour from radiation exposure.
Frequently asked questions
Do you have additional questions? No problem, let us help you through the process
At Queensmith, we work with diamonds independently graded by the GIA and IGI, who provide a globally-renowned, highly accurate grading service. The diamonds are colour graded upside down to minimise light interference, and placed on a pure white background before being compared to master stones - until they find the perfect match. If a diamond looks between two grades, for example, F and G, it will be awarded the lesser grade, in this case G (this may be referred to as a G+ colour grade).
Scientifically, the highest and most valuable grade is D, which is entirely colourless and chemically pure. However, any diamond between D-F will appear colourless to the naked eye, and choosing F may save you a little money compared to D. Diamonds graded G or H have a slight touch of warmth, so you could consider them to save a little money, but they won’t be priced too differently.
Natural diamonds most commonly form within a spectrum ranging from completely colourless to shades of faint yellow and brown (the standard D to Z scale). However, rare atomic disruptions during formation can create natural 'Fancy Coloured Diamonds' in almost any hue, including pink, blue, green, and vivid yellow.
For a bright, classic look, the D to F range is ideal. Your choice should be guided by your choice of metal:
D, E, or F (colourless): Best for all rings, particularly platinum or white gold settings, which amplify yellow tints.
G or H (near-colourless): A good compromise for yellow or rose gold settings, as the warm metal naturally masks subtle tints.
On the standard grading scale, Z is the cheapest diamond colour grade. The lower the letter grade on the D to Z scale, the more noticeable the yellow or brown tint becomes. Because these tinted stones are far less rare and less in demand for traditional jewellery, they command the lowest prices.
Both G and H diamonds appear fairly colourless face-up to the naked eye, so they are both good choices. Eagle-eyed people can sometimes spot the warm tint of a G or H diamond, but most people wont. If you want a slightly higher purity tier for peace of mind, choose G. You actually shouldn’t see a huge price difference with diamonds graded slightly higher, like D-F diamonds which are in the ‘colourless zone’.
Do you have additional questions? No problem, let us help you through the process
