The hex color #3f00d2 is a dark color. The web-safe version is Hex
#3300CC. A complementary color is
#C0FF2D. The grayscale version is
#5B5B5B. A 20% lighter version of the original color is
#7233FF, and Hex
#0C009F is the 20% darker color. If the color is saturated by 10%, you get
#3C00DE. If the color is desaturated by 10%, the color
#4209C6 is obtained.