The hex color #3f130d is a dark color. The web-safe version is Hex
#330000. A complementary color is
#C0ECF2. The grayscale version is
#202020. A 20% lighter version of the original color is
#724640, and Hex
#0C0000 is the 20% darker color. If the color is saturated by 10%, you get
#42120B. If the color is desaturated by 10%, the color
#3C140F is obtained.