The hex color #3d397f is a dark color. The web-safe version is Hex
#333366. A complementary color is
#C2C680. The grayscale version is
#525252. A 20% lighter version of the original color is
#706CB2, and Hex
#0A064C is the 20% darker color. If the color is saturated by 10%, you get
#3B3784. If the color is desaturated by 10%, the color
#3F3B7A is obtained.