Despite its terminology, diamond colour actually means the lack of colour in diamonds. In nature, most white diamonds have a slight tint of yellow.
Therefore, the diamond trade has a colour grading scale based on the amount of yellow present in a diamond, which is visible when viewed face down through the pavilion using daylight equivalent light. The higher the colour grade of the diamond, the more colourless that diamond is.
Completely colourless diamonds are rare, which is why they come with a higher pricing premium. But deciding whether or not you want to spend more on diamond colour grade will depend on the size and shape of the diamond that you are considering too.
The Gemmological Institute of America (GIA) colour scale is the industry standard for diamond grading. The GIA diamond colour grades range from D (colourless) to Z (light yellow or brown).
Colour is more visible in larger diamonds. So if you're buying a diamond under 1 carat, you might only need a stone graded I, J or K. Then again, diamonds over 1 carat should be H colour-graded or higher otherwise a tint could be visible.
You will also find that certain fancy-shaped diamonds hide colour better than others and can cost up to 25% less than the most desirable round-cut diamond.
If your diamond is going to be set in a precious metal like 18 carat yellow or rose gold, you should consider a diamond with a slightly lower colour grade. The warmer colour tones of these metals will highlight the bright white appearance of the diamond rather than any perceivable tint.
You may even decide that colour is a good thing. After all, diamonds occur in the natural rainbow spectrum of colours - red, orange, yellow, green, blue, pink, purple, and more. Around 1 in every 10,000 diamonds possess natural colour, and the more intense the colour, the more valuable the diamond.
Fancy-coloured diamonds are graded on a separate colour scale and can be even more valuable than white diamon