The hex color #71b521 is a light color. The web-safe version is Hex
#66CC33. A complementary color is
#8E4ADE. The grayscale version is
#6D6D6D. A 20% lighter version of the original color is
#A4E854, and Hex
#3E8200 is the 20% darker color. If the color is saturated by 10%, you get
#71BC19. If the color is desaturated by 10%, the color
#71AE29 is obtained.