The hex color #404df5 is a dark color. The web-safe version is Hex
#3366FF. A complementary color is
#BFB20A. The grayscale version is
#818181. A 20% lighter version of the original color is
#7380FF, and Hex
#0D1AC2 is the 20% darker color. If the color is saturated by 10%, you get
#3A48FF. If the color is desaturated by 10%, the color
#4652E9 is obtained.