The hex color #312e7c is a dark color. The web-safe version is Hex
#333366. A complementary color is
#CED183. The grayscale version is
#494949. A 20% lighter version of the original color is
#6461AF, and Hex
#000049 is the 20% darker color. If the color is saturated by 10%, you get
#2F2B81. If the color is desaturated by 10%, the color
#333177 is obtained.