The hex color #3f3566 is a dark color. The web-safe version is Hex
#333366. A complementary color is
#C0CA99. The grayscale version is
#494949. A 20% lighter version of the original color is
#726899, and Hex
#0C0233 is the 20% darker color. If the color is saturated by 10%, you get
#3E3369. If the color is desaturated by 10%, the color
#403763 is obtained.