Diamond colour refers to the absence of colour in a diamond. The closer a diamond is to being completely colourless, the higher its value. Fancy-coloured diamonds, such as pinks and blues, are an exception to this rule, as they are prized for their vivid hues. Most diamonds sold in jewellery stores range from colourless to near-colourless, with subtle hints of yellow or brown.
The Gemological Institute of America (GIA) established the diamond colour scale in the 1940s to standardize grading internationally. The scale starts with the letter D, representing colourless diamonds, and continues through to Z, indicating diamonds with noticeable colour. Each letter grade corresponds to a defined range of colour appearance. Diamond colour is assessed by comparing each stone to master diamonds under controlled lighting and viewing conditions.
Diamonds can display subtle hues such as yellow, brown, or gray. While some shades are less desirable in traditional white diamonds, others, like light brown "champagne" tones, have unique appeal. Understanding a diamond's hue can help in selecting complementary settings or matching stones.
Grades D, E, and F represent colourless diamonds, which are rare and highly valuable:D Colour: Completely colourless, offering a pure, icy appearance.E Colour: Nearly indistinguishable from D to the untrained eye, with exceptional brightness.F Colour: Very faint tint visible only to experts, still considered colourless.
Grades G, H, I, and J are classified as near-colourless. These diamonds may display slight warmth, particularly in larger stones or certain lighting conditions, but they appear bright and beautiful to most observers:G Colour: The highest grade of near-colourless diamonds, appearing mostly colourless.H Colour: Subtle warmth detectable under close inspection.I Colour: Slightly more noticeable tint, still attractive in most settings.J Colour: Warmth becomes more evident, pairing well with yellow or rose gold settings.
Diamonds graded N–R and S–Z display increasingly noticeable colour. These stones are valued for specific aesthetic preferences and are often more affordable. Beyond Z, diamonds are classified as Fancy Colour.
N Colour: Falls in the Very Light Colour category and generally exhibits very light yellow colour in normal lighting conditions. O Colour: Appears very light yellow and shows a warm tone when mounted or unmounted. P Colour: Displays very light yellow, with increasing visibility as you move down the scale. Q Colour: Shows a noticeable light yellow tint in normal lighting conditions. R Colour: Similar to Q, with a noticeable light yellow tint under normal lighting.
S Colour: At the top of the Light Colour grade, showing distinct light yellow tones. T Colour: Exhibits distinct light yellow tones, often sought for warm aesthetics. U Colour: Substantial light yellow visible both mounted and unmounted. V Colour: Shows warm light yellow tones in normal lighting conditions. W Colour: Exhibits substantial light yellow tones, often desired for warm hues. X Colour: Similar to W, with substantial noticeable colour. Y Colour: Displays substantial yellow tones in normal lighting. Z Colour: The deepest yellow in the D–Z scale; diamonds beyond Z are graded as Fancy Colour.
GIA gemologists grade diamonds by comparing them to master stones under controlled lighting and precise conditions. This rigorous process ensures consistency and accuracy.While many colour distinctions are imperceptible to the untrained eye, they can have a significant impact on a diamond’s value and price. Two diamonds with identical clarity, cut, and carat weight may differ drastically in price based solely on their colour grade.
Fluorescence is a natural property that causes about 35% of diamonds to emit visible light when exposed to ultraviolet (UV) rays. The most common fluorescence colour is blue, which can offset yellowish tones, making a diamond appear whiter in sunlight. However, excessive fluorescence can sometimes cause a diamond to appear hazy or oily, which may reduce its value.
Before the GIA introduced the D–Z grading scale, inconsistent systems were in use, including numerical scales and subjective terms like "blue white." To avoid confusion, the GIA opted to start fresh with the letter D, unassociated with previous grading practices.
Colour plays a crucial role in determining a diamond’s value and appearance. While colourless diamonds are traditionally the most sought-after, diamonds with subtle warmth are gaining popularity for their timeless appeal. Choosing the right diamond involves balancing colour with other factors like cut, clarity, and carat weight.
Exact colour matching isn’t always necessary, but harmony is key. Pairing a warm centre diamond with cooler side stones may accentuate the centre diamond’s tint, while colourless side stones can enhance the brilliance of a colourless centre diamond. Staying within 1–2 colour grades ensures a cohesive look.
When deciding between a Z-colour diamond and a Fancy Colour diamond, consider the colour differences between them and the overall aesthetic appeal. Z-colour diamonds, with their warm light yellow tones, are perfect for those who prefer a softer and more subtle look. On the other hand, Fancy Colour diamonds, which extend beyond Z into vibrant hues, are ideal for those seeking a bolder statement colour. Fancy Colours are rarer and can be more expensive, but they offer a unique way to express individuality and style.
We are highly selective about the diamonds & coloured gemstones we offer in our Gem Vault. Every stone is carefully selected by our founder—a certified gemmologist with the International Gem Society (IGS) and an accredited diamond grader with the Gemmological Association of Australia (GAA). Each and every stone is assessed with precision and care, upholding our strict standards of quality, traceability, and ethical sourcing. Explore the Gem Vault to discover our curated collection of loose diamonds and coloured gemstones, or contact us to source something specific for your design.
