Colour
A diamond with the highest color grade is the diamond with the least amount of color. The highest grade is D, which indicates that a diamond is colorless, and therefore extremely rare and valuable. An E grade indicates minute traces of colour that can only be detected by an expert. An F grade indicates slight traces of color. A diamond in the G-H range is near-colorless, with traces of yellow generally visible only when compared with whiter diamonds. I-J diamonds are also near-colorless, with color slightly detectable to the unaided eye. K-M, diamonds begin to display noticeable color.

Color differences in diamonds are very subtle. They are therefore graded under controlled lighting conditions and are compared to a master set of diamonds for accuracy. Ask your retailer to show you a variety of color grades next to one another to help you to recognize the differences. Although the presence of color diminishes a diamond’s value and cost, a bright, intense yellow-colored diamond is considered a "fancy" and is normally priced at a premium. Red, blue, pink, purple and green diamonds are also called fancies. They are rare and valuable.