The hex color #51a428 is a dark color. The web-safe version is Hex
#669933. A complementary color is
#AE5BD7. The grayscale version is
#5F5F5F. A 20% lighter version of the original color is
#84D75B, and Hex
#1E7100 is the 20% darker color. If the color is saturated by 10%, you get
#50AB23. If the color is desaturated by 10%, the color
#529D2E is obtained.