The hex color #51e23f is a light color. The web-safe version is Hex
#66CC33. A complementary color is
#AE1DC0. The grayscale version is
#7B7B7B. A 20% lighter version of the original color is
#84FF72, and Hex
#1EAF0C is the 20% darker color. If the color is saturated by 10%, you get
#4DEC39. If the color is desaturated by 10%, the color
#55D845 is obtained.