The hex color #664c00 is a dark color. The web-safe version is Hex
#663300. A complementary color is
#99B3FF. The grayscale version is
#3B3B3B. A 20% lighter version of the original color is
#997F33, and Hex
#331900 is the 20% darker color. If the color is saturated by 10%, you get
#6A4E00. If the color is desaturated by 10%, the color
#624A06 is obtained.