An indication of the hue, tone, and saturation of a diamond. See Color Grade.

The normal color scale, as defined by GIA:

D, E, F = Colorless

G, H, I, J = Near Colorless

K, L, M = Faint Yellow

N, O, P, Q, R = Very Light Yellow

S, T, U, V, W, X, Y, Z = Light Yellow

 

Some fancy colored diamonds:

dias_colored