Diamond color is graded on a scale from D to Z, with D being the whitest (and thus the most desirable and expensive) color of diamond. Each grade going up from D indicates slightly greater appearance of color (usually yellow or brown) in the stone.
However, below a certain point the human eye will not be able to tell the difference between a perfectly white D color stone and a less perfect version like a G color, unless they are sitting side by side in front of you. That differentiating line seems to be drawn around the K level, so we typically advise this as the lowest color grade you consider when shopping for a diamond. Here’s the color scale as it appears on GIA.edu.
Below we have a comparison of 1 carat diamonds in every color grade from D - K. All of these diamonds are VS1 clarity, GIA Excellent cut/symmetry/polish, and none fluorescence. We also opted for diamonds with high cut scores (our internal metric for light performance). You can filter by cut score for round diamonds in StoneAlgo's Diamond Search Engine
Click on an image to see more details.
Can you tell the difference between these color grades with your naked eye?
D color diamonds should always appear perfectly white with no tinge of color. D color is the highest grade a diamond can receive from the GIA, AGS, and other grading agencies. The GIA’s color grading scale starts at D in order to differentiate from other, older grading agencies who used letters A – C or numerals to represent color grades. D color diamonds don’t benefit from fluorescence like lower color grades can because they are already perfectly white.
E color diamonds are grouped together with D and F color as the “colorless” range of diamonds by the GIA. E color diamonds should look totally white, but they do possess some slight tinge of color that separates them from the D color diamonds.
F color diamonds are considered colorless diamonds by the GIA and are nearly indistinguishable from D and E color diamonds to the naked eye.
G color diamonds are the highest color grade in the “near colorless” range of diamonds, but most people can’t tell the difference between a G color diamond and a colorless diamond. It’s also worth noting that most jewelers recommend None, Faint, or Medium fluorescence with a G color diamond.
H color diamonds are right in the sweet spot when it comes to maximizing appearance and value, which is why they’re one of the most popular choices for diamond buyers. I’d also note that most jewelers recommend None, Faint, or Medium fluorescence with an H color diamond.
I color diamonds offer great value while still looking nice and white to the naked eye in any color of setting. Most jewelers recommend you consider faint or medium fluorescence with I color diamonds if you want to get even more value, and a little fluorescence can actually help these diamonds appear whiter.
J color diamonds are the best value of the near colorless diamond range and will still look nice and white in any color setting. Most jewelers recommend you consider faint or medium fluorescence with a J color diamond, since some fluorescence can help a J color diamond appear even whiter.
K color diamonds are the first step in the faintly colored class of diamonds and a favorite of buyers looking to stretch their budget. While K color diamonds can “face up white”, they typically show obvious color when viewed from the side. All diamonds appear whiter once placed in a metal setting.