The hex color #31212c is a dark color. The web-safe version is Hex
#333333. A complementary color is
#CEDED3. The grayscale version is
#2A2A2A. A 20% lighter version of the original color is
#64545F, and Hex
#000000 is the 20% darker color. If the color is saturated by 10%, you get
#32202C. If the color is desaturated by 10%, the color
#30222C is obtained.