The hex color #645c4d is a dark color. The web-safe version is Hex
#666666. A complementary color is
#9BA3B2. The grayscale version is
#5A5A5A. A 20% lighter version of the original color is
#978F80, and Hex
#31291A is the 20% darker color. If the color is saturated by 10%, you get
#655C4C. If the color is desaturated by 10%, the color
#635C4E is obtained.