The hex color #312c9c is a dark color. The web-safe version is Hex
#333399. A complementary color is
#CED363. The grayscale version is
#535353. A 20% lighter version of the original color is
#645FCF, and Hex
#000069 is the 20% darker color. If the color is saturated by 10%, you get
#2E28A3. If the color is desaturated by 10%, the color
#343095 is obtained.