In theory, the rule is simple, the most transparent and absent of color the diamond is, the higher its quality, but of course, all the rules have their exceptions.

From 1999 a tool called Gran Full Spectrum Colorimeter DC2000fs created by Gem Instruments, has been used for diamond color classification. So accurate it is, that allow us to break the same color tone into five different grades. So this is, every letter (representing the tone), for example F, can be divided into F1, F2, F3, F4 and F5, being F1 the closest to the E tone, and the F4 the borderline with G.

The most expensive being the D and going down in price towards the end, following the ABC.

The diamond color scale starts with the D, E and F being the purest of them all, and considered not colored. Then the G, H, I, J follow with being considered almost not colored. The classes K, L and M have very little color tones, N, O, P, Q, R have very light yellow tone, and S, T, U, V, W, X, Y and Z having a clear yellow to yellow colors.

There are too, breaking the rules, some other variations of diamonds, like the white-blue ones, that are extremely rare, and therefore, valuable, other varieties can be the pink toned, green toned, champagne colored...

But hey! Not everyone has access to that kind of tools! So true, that is because the best way to appreciate the color eye naked is placing the diamond in diagonal perspective over a white background. Sure it will not be super accurate, but is better than nothing. In this section, same than with the clarity section, we would advise to have a second opinion from an expert. Remember this guide is a mere initiation to the diamond appraisal.