The hex color #311ad1 is a dark color. The web-safe version is Hex
#3333CC. A complementary color is
#CEE52E. The grayscale version is
#5F5F5F. A 20% lighter version of the original color is
#644DFF, and Hex
#00009E is the 20% darker color. If the color is saturated by 10%, you get
#2C13DC. If the color is desaturated by 10%, the color
#3621C6 is obtained.