The hex color #51a029 is a dark color. The web-safe version is Hex
#669933. A complementary color is
#AE5FD6. The grayscale version is
#5E5E5E. A 20% lighter version of the original color is
#84D35C, and Hex
#1E6D00 is the 20% darker color. If the color is saturated by 10%, you get
#50A724. If the color is desaturated by 10%, the color
#52992E is obtained.