Diamond Color Chart: Every Grade From D to Z

A diamond color chart is the GIA D to Z scale laid out in order. It grades the absence of colour in a white diamond. D shows no colour a grader can detect; Z is a light yellow or brown, still not saturated enough to be called a fancy colour.

Every laboratory grading to an international standard uses this scale or a direct equivalent, and IGI grades lab grown diamonds on it.

The scale starts at D for a reason GIA states plainly: to avoid confusion, comparison or association with previous systems. Before the D to Z scale, sellers used A, B and C, along with numbers and words that meant different things in different shops. Starting at D made the new scale impossible to mistake for any of them.

The strip above places the 23 letters in their five categories. The bands are illustrative of the direction of tint rather than calibrated samples; a printed or screen colour cannot reproduce the difference between an F and a G. The dashed line marks where Draco stops. Every stone in the catalogue is E or F, two of the three colourless grades.

D, E and F are colourless. A grader separates them by comparison against masterstones, and the difference between adjacent letters is, in GIA's words, often not noticeable to the untrained eye.

D is the top of the scale. E and F are colourless stones a grader could tell from a D masterstone under controlled light. No one else is likely to tell them apart on the hand.

G, H, I and J are near colourless. G is the first grade at which a grader detects colour. Through H the stone still reads white face up in most settings. By I and J, warmth begins to be detectable face up, especially in white metal and in larger stones, though both grades read white against yellow gold.

K, L and M are faint. The tint is readily identified by a grader and, in larger stones or white metal, by a buyer. This is the band where colour becomes a design decision rather than a grading footnote. Warm stones in warm metal are a deliberate look, and a K in yellow gold is a legitimate choice, not a compromise.

N to Z are very light and light. Colour is visible in the stone and increases through the range. At Z the stone is distinctly yellow or brown. One step beyond Z it leaves this chart entirely and is graded as a fancy colour, where saturation is the goal rather than the flaw.

Colour is not graded by looking at a stone and forming an impression. It is graded by comparison. The stone is placed beside masterstones of established grade, under controlled lighting, and the grader finds where it falls between them.

GIA describes the correct way to evaluate colour as precise conditions, under controlled lighting, where stones are compared to masterstones with established colour grades. Two details of that method explain almost everything about how colour grades behave in the real world.

The first is that grading isolates body colour. Laboratories examine stones in a way that removes the brilliance of the crown and the reflections of any setting, so that only the colour of the material itself is measured. The second is that the reference is another diamond, not a memory or a chart. A grader is not asking whether the stone looks white; they are asking whether it is whiter or warmer than the E masterstone beside it.

Lab grown diamonds are graded by the same comparison. In a grown stone the colour has a known cause: nitrogen admitted during growth produces yellow, boron produces blue, and the absence of both produces a colourless stone. Growers control the chemistry, which is why grown material clusters toward the top of the scale. The grade is still assigned by a laboratory such as IGI, not by the grower.

The chart has 23 grades. On the hand, in ordinary light, the eye separates about three: stones that read white, stones that read warm if you look, and stones that read warm at a glance. Where the lines fall depends on three things the chart does not show: the metal, the carat weight and the light.

A laboratory grades face down, to remove the crown's brilliance and see only body colour. A buyer sees the stone face up, where a well cut crown returns so much light that body colour is partly masked. This is why stones read whiter mounted than the grade suggests, and why a colour grade is a floor for what you will see rather than a description of it.

This is the reasoning behind the Draco floor. Every diamond in the catalogue is E or F, two of the three colourless grades. That places every stone above the point where colour can be detected face up, in any metal and at any size in the range. It removes colour from the decision entirely. Because the floor applies to every piece, colour is not a price variable at Draco; the price follows carat weight, metal and setting labour.

The setting is the largest influence on how a colour grade reads, and it works in a predictable direction. White gold and platinum are neutral; they show the stone's own colour, so a warm stone reads warm against them.

Yellow gold and rose gold reflect their own colour up into the stone, so a faint tint disappears against warmth that is already there. A G or H reads white in yellow gold. The same stone in platinum is where a careful eye begins to notice.

Carat weight works the other way. A larger stone has more body to see through, so the same grade shows more colour as the stone grows. A grade that reads white at half a carat in a pendant can read warm at three carats in a solitaire in the same metal. Move up the chart as the stone gets bigger.

Draco sells every piece in sterling silver, 10K, 14K and 18K gold in white, yellow and rose, and platinum. The colour floor is the same E to F on all of them. The practical result is that the metal can be chosen purely for its own look. No combination of metal and size in the catalogue exposes a stone below the colourless band. Metal pricing is a fixed percentage of the 10K base and is set out in the metal guide linked below.

Every Draco diamond is IGI certified at E to F colour and VS2 or better and ships with its certificate. The report can be provided on request before purchase and verified free at IGI.org.

Every piece carries 30 day returns, the Lifetime Authenticity Guarantee, free resizing, and free insured worldwide shipping to 25 markets, delivered duty paid with nothing collected at the door, and signature on delivery.

Because the colour floor is the same across the catalogue, a buyer here chooses a metal and a carat weight and not a letter. Browse the ring collection, or start a commission at create your piece. Fancy coloured lab grown diamonds, graded on their own scale, appear in the catalogue in pink, blue, yellow and cognac.