The hex color #3F367D is a dark color. The web-safe version is Hex
#333366. A complementary color is
#C0C982. The grayscale version is
#515151. A 20% lighter version of the original color is
#7269B0, and Hex
#0C034A is the 20% darker color. If the color is saturated by 10%, you get
#3D3381. If the color is desaturated by 10%, the color
#413979 is obtained.