The hex color #4f51a6 is a dark color. The web-safe version is Hex
#666699. A complementary color is
#B0AE59. The grayscale version is
#6D6D6D. A 20% lighter version of the original color is
#8284D9, and Hex
#1C1E73 is the 20% darker color. If the color is saturated by 10%, you get
#4C4EAC. If the color is desaturated by 10%, the color
#5254A0 is obtained.