The Gemval color grading system is a simplified modification of the Gemological Institute of America (GIA) color grading standards for natural gemstones. color grading standards for natural gemstones. Unlike GIA's standard color set, the Gemval web color system is designed to fit a 32-bit LCD computer monitor precisely and specifically to enable color recognition via a web interface.
This color grade method represents the core of Gemval's online appraisal system. It consists of 230 color patterns, 25 base hue sets and 1 grey scale. Additionally it is extended by 6 tones (very light, light, medium light, medium, medium dark and dark) and by 3 saturation grades (strong, very slightly greyish/brown and slightly greyish/brown).