Diamond colour ranges from D to Z. D represents near colourless and Z representing light yellow or brown. Why does it start with D you ask? When the system was first developed in the 1940s and 50s, they wanted to avoid confusion with gem grading systems already in operation of which there many; for example , AAA, AA, A,B, C – 0,1,2,3 and roman numerals I,II,III and arbitrary descriptions such as golconda or cape on fine white. So the system started with the letter D to avoid confusion and association with other systems.
D-Z COLOUR GRADING
It is a comparitive grading system in that the diamonds are compared to other diamonds of a known colour.
Most diamonds sold in jewellery would be in the colourless to near colourless range.
Without a base colour to compare it to most people will find it hard to guess the colour quality of a stone. Eyesight lighting conditions, room colour, background all
contribute to the difficulty. Saying this, most people will spot colour from H onwards in decent lighting conditions.
Whereas carat weight can shift prices in the thousands, colour will only cost you hundreds so its worth investing in a higher colour.
Generally speaking the less colour, the more valuable. The exception of course is fancy coloured diamonds such as pink or blue or the exceedingly rare red, which can command a much higher price than colourless diamonds.
While diamonds in the normal colour range are described in the D to Z range and the less colour present the more valuable, Fancy colour diamonds becomes more valuable the more intense the colour becomes.
The most common fancy colours are yellow and brown, while much more common than other colours they are still much rare than colourless diamonds.
Fancy colour diamonds come in almost any colour you can imagine from black to white. Red, green, purple and orange are the rarest fancy colours.