The hex color #3f56a3 is a dark color. The web-safe version is Hex
#336699. A complementary color is
#C0A95C. The grayscale version is
#686868. A 20% lighter version of the original color is
#7289D6, and Hex
#0C2370 is the 20% darker color. If the color is saturated by 10%, you get
#3B54A9. If the color is desaturated by 10%, the color
#43589D is obtained.