Several mathematical, notational, and verbal classifications exist and are used either as a part of a complete color grading scheme or individually and selectively for specific gemstones. Trying to make sense of all the standards and how they relate is like going down a rabbit hole. There is little agreement about which measures are best, and it seems that every gem lab wants to create their own standards, but in the end, we
are left with a default grade, which is just someone’s initial impression of the color.

The Pantone system, with its color swatches and alluring designations, is popular and used in multiple industries, but its focus is also on planar surfaces. All of these flat color models were developed for computers and printing. They cannot accommodate the effects of thickness in gemstones. They’re fine for objects like paintings, illustrations, textiles, and walls, but not for gems.