What is diamond colour?

Diamonds come in a wide variety of colours, from colourless through near-colourless and even colours like blue or green.

The GIA colour grading system assesses the presence or absence of colour in the most commonly occurring colourless to light yellow. The yellow colour tint is a reflection of the trace levels of nitrogen within the diamond crystal structure.

Diamond colour scale:

GIA’s colour-grading scale for diamonds is the industry standard. The scale begins with the letter D, representing colourless, and continues with increasing presence of colour to the letter Z, or light yellow.

Diamond Colour Chart:

At Mill & Way we prefer to work with diamonds that are in the ‘Colourless’ and ‘near colourless’ range on the GIA diamond scale. We prefer to work with the highest colour range, but we do find that some customers prefer the slighter warmer colour tones.

D, E, F


G, H, I, J

Near Colourless 

K, L, M


N, O, P, Q, R

Very Light 

S, T, U, V, W, X, Y, Z


Why does the GIA colour grading system start at D?

Before GIA developed the D-Z Colour Grading Scale, a variety of other systems were loosely applied. These included letters of the alphabet (A, B and C, with multiple A’s for the best stones), Arabic (0, 1, 2, 3) and Roman (I, II, III) numerals, and descriptions such as “gem blue” or “blue white.”

The result of all these grading systems was inconsistency and inaccuracy. Because the creators of the GIA Colour Scale wanted to start fresh, without any association with earlier systems, they chose to start with the letter D—a letter grade normally not associated with top quality,

Does diamond colour matter?

Diamond colour is a completely personal preference. Some customers do prefer stones in the colourless range (D, E and F) as the higher colours are considered the most captivating. Whereas other customers prefer the charm of the warmer tones of the new near colourless range (G, H, I and J).

Fancy coloured diamonds

When does colour become a ‘fancy’ colour?

When a diamond falls outside of GIA’s D-to-Z colour scale, it is considered a coloured diamond (sometimes called a fancy-colour diamond). This includes all colours other than colourless to light yellow or brown.

On GIA Coloured Diamond Grading Reports, coloured diamonds are graded in order of increasing colour strength, from Faint, Very Light, Light, Fancy Light and Fancy to Fancy Intense, Fancy Vivid, Fancy Dark and Fancy Deep. Fancy Intense and Fancy Vivid generally command higher prices.

When does colour become a benefit?

Most diamonds used in jewellery range from colourless to light yellow and are graded on a scale from D (colourless) to Z (light yellow). Those with less colour, or closer to colourless, are generally more valuable.

Diamonds with deeper shades of yellow (more colour than Z) are graded differently and given a fancy-colour grade. For these coloured diamonds, a more vibrant colour typically means higher value.

Please contact us if you are looking for a yellow or fancy coloured diamond.

Black diamonds

The opaque colour of black diamonds is caused by dark inclusions. These can create an interesting and stylish alternative to the traditional engagement ring.

Please get in touch if you would like a black diamond in one of our rings!

What are Salt and Pepper diamonds?

Salt and pepper diamonds are stones with a high level of black and white inclusions resulting in a speckled greyish appearance. These give a modern twist to the traditional diamond.

Please get in touch if you would like a Salt and Pepper diamond in one of our designs!