The hex color #c8313d is a dark color. The web-safe version is Hex
#CC3333. A complementary color is
#37CEC2. The grayscale version is
#676767. A 20% lighter version of the original color is
#FB6470, and Hex
#95000A is the 20% darker color. If the color is saturated by 10%, you get
#D22C39. If the color is desaturated by 10%, the color
#BE3641 is obtained.