The hex color #3100df is a dark color. The web-safe version is Hex
#3300CC. A complementary color is
#CEFF20. The grayscale version is
#5B5B5B. A 20% lighter version of the original color is
#6433FF, and Hex
#0000AC is the 20% darker color. If the color is saturated by 10%, you get
#2D00EC. If the color is desaturated by 10%, the color
#3509D2 is obtained.