The hex color #3d3e4d is a dark color. The web-safe version is Hex
#333366. A complementary color is
#C2C1B2. The grayscale version is
#434343. A 20% lighter version of the original color is
#707180, and Hex
#0A0B1A is the 20% darker color. If the color is saturated by 10%, you get
#3C3E4E. If the color is desaturated by 10%, the color
#3E3E4C is obtained.