The hex color #31923b is a dark color. The web-safe version is Hex
#339933. A complementary color is
#CE6DC4. The grayscale version is
#555555. A 20% lighter version of the original color is
#64C56E, and Hex
#005F08 is the 20% darker color. If the color is saturated by 10%, you get
#2D9838. If the color is desaturated by 10%, the color
#358C3E is obtained.