The hex color #51bb1c is a light color. The web-safe version is Hex
#66CC33. A complementary color is
#AE44E3. The grayscale version is
#636363. A 20% lighter version of the original color is
#84EE4F, and Hex
#1E8800 is the 20% darker color. If the color is saturated by 10%, you get
#4FC415. If the color is desaturated by 10%, the color
#53B223 is obtained.