The hex color #81d50f is a light color. The web-safe version is Hex
#99CC00. A complementary color is
#7E2AF0. The grayscale version is
#777777. A 20% lighter version of the original color is
#B4FF42, and Hex
#4EA200 is the 20% darker color. If the color is saturated by 10%, you get
#82DE05. If the color is desaturated by 10%, the color
#80CC19 is obtained.