Diamonds have colorless series and colored series. Color grading is not applicable to colored diamonds. Colorless series is divided into d to z grades. Grade d is very rare and completely colorless. E grade is also rare and colorless. Class F is a high-quality diamond, colorless. G-H grade has high value and is close to colorless.

The color of diamond ring is divided into two series, the common ones are colorless series and color series. The classification of color grades does not apply to colored diamonds. Diamonds can be divided into "D" and "Z" according to the color classification made by GIA of Gemological Institute of America.

D grade is the highest color grade of diamonds, which is very rare and completely colorless. Grade E is also a very rare diamond, colorless, and only a gemologist can detect a trace of color. Class F is still a high-quality diamond, colorless, and jewelry experts can only detect a few colors.

G-H diamonds of this color grade are also of high value, close to colorless and slightly colored compared with diamonds of higher color grade. The value of I-J diamonds is relatively high, close to colorless, and can be detected with a little color. K-M diamonds are dark in color and poor in fire color, so it is not recommended to buy them.