What is it?

ColorCodex System for Referencing Color


What is it?

ColorCodex color referencing system is an easy to use, intuitive system for comparing and referencing the color of faceted gemstones. It was developed by gemologists as a tool to allow the industry to establish the color of a gemstone in a manner that is both accurate and repeatable. Color is a complex world of hue, saturation and tone.

All of these factors combine to create the particular color that we see, with a seemingly limitless variety of shades and nuances. Gemstones add an intricate dimension, as they are transparent bodies which through faceting present a mosaic of brightly colored or more subdued reflections, as well as blackened areas of extinction. All of these areas then fluctuate and shift as the gemstone is tipped and rotated.


Real World Applications

The ColorCodex™ referencing system was designed to support a variety of applications including but not limited to:

  • To train gemologists, jewelers, appraisers, and gem dealers in the nuances of color and how tone influences the appearance of color.

  • To help the industry at large set parameters for gem varieties that are defined by color. This includes the differentiation between Ruby ad Pink Sapphire varieties, Imperial and Precious Topaz, Paraiba-Type Tourmaline, Rhodolite and other garnet varieties, etc.

  • To set parameters for fanciful color terms used within the trade, such as Pigeon Blood, Royal Blue, and others.

  • To allow appraisers and insurers to establish a color reference so that should there be a loss, a gem of similar color and quality can be found to replace it.

  • To assist jewelers and gem dealers when trying to create a pair or suite of gems by helping to locate matches.

  • To educate consumers, students, hobbyists, etc. in the area of color referencing within gemstones.


ColorCodex is a color referencing system specifically developed to facilitate the communication of color as it appears in faceted gemstones. It consists of colored windows that have a reflective and textured surface that mimics the appearance of color as it is represented in a gemstone. Color is communicated in various ways based off of personal experiences, oberservations, and descriptions. In order to clarify colors to be understood universally, the ColorCodex referencing system uses a numeric value.


The system includes a total of 65 different hues of color represented on 13 ColorCodex sheets. Each hue is represented by its own column which is then divided into 8 windows that depict the varying intensity or saturation of that specific color. The colors, or hues, are evenly numbered horizontally across the page from 10 through 138. The vertical windows showing intensity are given odd numbers from 03 through 17. Combining these two numeric values (e.g. 22 – 07) defines not only a specific color (column 22), but also its level of saturation (level 07).