The hex color #645c4c is a dark color. The web-safe version is Hex
#666633. A complementary color is
#9BA3B3. The grayscale version is
#595959. A 20% lighter version of the original color is
#978F7F, and Hex
#312919 is the 20% darker color. If the color is saturated by 10%, you get
#655C4B. If the color is desaturated by 10%, the color
#635C4D is obtained.