Natural fancy brown diamonds are assessed according to intensity of color, or a combination of saturation and tone. Tone refers to the lightness or darkness of a brown diamond, and the continuum in between.
The following terms are used loosely to describe the intensity and purity of the brown tone in polished diamonds;
Top Light Brown
Medium Brown (champagne)
Brown (dark champagne)
Dark Brown (cognac)
Stuller also carries top light brown (TLB), which refers to a very light shade of brown stones. On the diamond color scale, these diamonds would be compared to L-M color. In the figure above, these diamonds are displayed as C1-C3.