The hex color #3f3d3f is a dark color. The web-safe version is Hex
#333333. A complementary color is
#C0C2C0. The grayscale version is
#3E3E3E. A 20% lighter version of the original color is
#727072, and Hex
#0C0A0C is the 20% darker color. If the color is saturated by 10%, you get
#3F3D3F. If the color is desaturated by 10%, the color
#3F3D3F is obtained.