The hex color #81031c is a dark color. The web-safe version is Hex
#990033. A complementary color is
#7EFCE3. The grayscale version is
#353535. A 20% lighter version of the original color is
#B4364F, and Hex
#4E0000 is the 20% darker color. If the color is saturated by 10%, you get
#890019. If the color is desaturated by 10%, the color
#79081F is obtained.