The hex color #3d29e5 is a dark color. The web-safe version is Hex
#3333CC. A complementary color is
#C2D61A. The grayscale version is
#6E6E6E. A 20% lighter version of the original color is
#705CFF, and Hex
#0A00B2 is the 20% darker color. If the color is saturated by 10%, you get
#3822F1. If the color is desaturated by 10%, the color
#4230D9 is obtained.