The hex color #669900 is a dark color. The web-safe version is Hex
#669900. A complementary color is
#9966FF. The grayscale version is
#555555. A 20% lighter version of the original color is
#99CC33, and Hex
#336600 is the 20% darker color. If the color is saturated by 10%, you get
#68A000. If the color is desaturated by 10%, the color
#649209 is obtained.