The hex color #645c1e is a dark color. The web-safe version is Hex
#666633. A complementary color is
#9BA3E1. The grayscale version is
#4A4A4A. A 20% lighter version of the original color is
#978F51, and Hex
#312900 is the 20% darker color. If the color is saturated by 10%, you get
#675E1A. If the color is desaturated by 10%, the color
#615A22 is obtained.