When white diamonds are color graded, gemologists use the Diamond Color Scale. This is a scale from D to Z, meaning that white diamonds have 17 possible color grades.

"Diamonds that fall beyond Z on the color scale are considered fancy colored diamonds, which actually are the rarest to find in nature and are extraordinarily expensive," Shah says.

Diamonds are graded on a color scale from D (completely colorless) to Z (light yellow or brown). The less color a diamond has, the more valuable and desirable it is.

The GIA color scale runs from D to Z, with D being colorless and Z being light. “When they talk about color, they’re really talking about the lack of color,” Shor says.