Yellow diamonds and colored diamond, including red diamonds, pink diamond, blue diamonds, purple diamonds and gold diamonds, are favored by collectors because of their bright colors and extremely rare output, and their prices have doubled.

Yellow diamonds were exposed to nitrogen for 100 years before they gained color. Almost all "white" diamonds are slightly yellow or brown. According to the standard color scale of Gemological Institute of America (GIA), gemstones of grade D, E or F are "colorless". According to its standard, K-M diamonds are "light yellow" and N-R diamonds are "extremely light yellow". The colors of the remaining letters range from "light yellow" to "dark yellow". True yellow diamonds only account for 0. 1% of natural diamonds.