The hex color #3d3d7f is a dark color. The web-safe version is Hex
#333366. A complementary color is
#C2C280. The grayscale version is
#535353. A 20% lighter version of the original color is
#7070B2, and Hex
#0A0A4C is the 20% darker color. If the color is saturated by 10%, you get
#3B3B83. If the color is desaturated by 10%, the color
#3F3F7B is obtained.