The hex color #21af4c is a dark color. The web-safe version is Hex
#339933. A complementary color is
#DE50B3. The grayscale version is
#5F5F5F. A 20% lighter version of the original color is
#54E27F, and Hex
#007C19 is the 20% darker color. If the color is saturated by 10%, you get
#1BB74A. If the color is desaturated by 10%, the color
#27A74E is obtained.