A diamond’s color impacts both its appearance and its value. When we speak of a diamond’s color, we are usually referring to the presence or absence of color in white diamonds. Color is a result of the composition of the diamond, and it never changes over time. The diamond color grading scale is a continuum of color intensities ranging from colorless to obviously tinted.
Color grading of diamonds in the normal range is performed by viewing the diamond at a viewing distance of 12-15 inches. The color grades are very small increments along this continuum starting at D and progressing to Z.
Diamonds are divided into 5 general categories, or diamond color grades, ranging from “Colorless” to “Light Yellow” with a lettering system from D to Z. The letter represents the amount of color present in each diamond when graded by a gemologist.