GIA’s Color Grading Scale
GIA’s system for color-grading colored diamonds was developed in the mid-1950s and revamped in the mid-1990s. The system expresses color using the attributes of hue (the characteristic color), tone (the color’s relative lightness or darkness), and saturation (the strength or weakness of the color). Using controlled viewing conditions and color comparators, the grader determines the stone’s color from one of 27 hues. The fancy grade describes the stone’s tone and saturation with romantic names like “Fancy Light,” “Fancy Intense,” and “Fancy Vivid.”
Today, the GIA color grading system for colored diamonds is used worldwide. Many of the most famous colored diamonds, including the blue Hope, the Dresden Green, and the Hancock Red, have been examined by the GIA laboratory.
GIA offers two types of grading reports for colored diamonds. The GIA Colored Diamond Grading Report contains the same comprehensive information as the GIA Diamond Grading Report. In addition, the GIA Colored Diamond identification and Origin Report, known as the color-only report, gives a color grade and the nature of the color.