The hex color #3d1b5d is a dark color. The web-safe version is Hex
#333366. A complementary color is
#C2E4A2. The grayscale version is
#3C3C3C. A 20% lighter version of the original color is
#704E90, and Hex
#0A002A is the 20% darker color. If the color is saturated by 10%, you get
#3D1860. If the color is desaturated by 10%, the color
#3D1E5A is obtained.