The hex color #51a333 is a dark color. The web-safe version is Hex
#669933. A complementary color is
#AE5CCC. The grayscale version is
#626262. A 20% lighter version of the original color is
#84D666, and Hex
#1E7000 is the 20% darker color. If the color is saturated by 10%, you get
#4FA92E. If the color is desaturated by 10%, the color
#539D38 is obtained.