The hex color #31434c is a dark color. The web-safe version is Hex
#333333. A complementary color is
#CEBCB3. The grayscale version is
#404040. A 20% lighter version of the original color is
#64767F, and Hex
#001019 is the 20% darker color. If the color is saturated by 10%, you get
#30434D. If the color is desaturated by 10%, the color
#33434B is obtained.