The hex color #3d39b0 is a dark color. The web-safe version is Hex
#333399. A complementary color is
#C2C64F. The grayscale version is
#626262. A 20% lighter version of the original color is
#706CE3, and Hex
#0A067D is the 20% darker color. If the color is saturated by 10%, you get
#3935B8. If the color is desaturated by 10%, the color
#413DA8 is obtained.