The hex color #3f3ee9 is a dark color. The web-safe version is Hex
#3333FF. A complementary color is
#C0C116. The grayscale version is
#777777. A 20% lighter version of the original color is
#7271FF, and Hex
#0C0BB6 is the 20% darker color. If the color is saturated by 10%, you get
#3938F4. If the color is desaturated by 10%, the color
#4544DE is obtained.