Colour grade: D to Z
The diamond colour grade says how little colour a white diamond has, on a scale from D to Z. D has no colour at all. By Z, a light yellow or brown shows.
- The scale starts at D, the top colourless grade, and runs to Z.
- Graders look at the diamond face down, in controlled light, next to master stones of known grade.
- Neighbouring grades look almost the same, yet the difference can change the price a lot.
Colour chart: D to Z in five groups
Odds in RXXO- D to FColourlessThe most chemically pure diamonds on the scale.1 in 100
- G to JNear colourlessColour is usually unseen except by trained graders.1 in 10
- K to MFaintColour is still hard to see for an untrained eye.1 in 7
- N to RVery lightColour can be seen in larger stones.1 in 3
- S to ZLightColour can be seen in stones of many sizes.1 in 2
In RXXO
In RXXO, D, E and F together are about 1 in 100. A single D is about 1 in 300.
D, E and F RXXO diamonds
Look closer
How it is graded
The diamond sits table down in highly controlled light and is compared with master stones, each one set at a letter.
Beyond Z
A yellow or brown stone with more colour than a Z, or a stone of another colour, is called a fancy colour diamond. Those have their own story. Diamond colours
Questions
What does D colour mean?
D is the top grade on the D to Z scale: a diamond with no colour at all. D, E and F are called colourless.
What is near colourless?
G, H, I and J. Their colour is usually unseen except by trained graders.
What comes after Z?
A diamond with more colour than Z, or a colour other than yellow, brown or grey, is a fancy colour diamond.
How is diamond colour graded?
The diamond is placed face down under controlled light and compared with master stones, each set at one letter of the D to Z scale.
How rare is a D colour diamond in RXXO?
About 1 in 300. D, E and F together are about 1 in 100.
RXXO numbers are the odds every mint draws from. Updated 8 October 2026.