The hex color #3f00ff is a dark color. The web-safe version is Hex
#3300FF. A complementary color is
#C0FF00. The grayscale version is
#6A6A6A. A 20% lighter version of the original color is
#7233FF, and Hex
#0C00CC is the 20% darker color. If the color is saturated by 10%, you get
#3B00FF. If the color is desaturated by 10%, the color
#430BF0 is obtained.