The hex color #3e3f5e is a dark color. The web-safe version is Hex
#333366. A complementary color is
#C1C0A1. The grayscale version is
#494949. A 20% lighter version of the original color is
#717291, and Hex
#0B0C2B is the 20% darker color. If the color is saturated by 10%, you get
#3D3E60. If the color is desaturated by 10%, the color
#3F405C is obtained.