When gemologists and jewelers talk of a gemstone’s hue, they are talking about its color. Hue is used in the Gemological Institute of Ameria’s (GIA) colored gem grading code and refers to the basic colors we see. The basic hues are red (R), orange (O), yellow (Y), green (G), blue (B), violet (V), and purple (P). When colors combine hues, the primary color is listed last and the modifying color is listed first. For example, a stone with a yellowish-green hue implies that the green hue is stronger than the yellow hue.
