The hex color #a66ff3 is a light color. The web-safe version is Hex
#9966FF. A complementary color is
#59900C. The grayscale version is
#ADADAD. A 20% lighter version of the original color is
#D9A2FF, and Hex
#733CC0 is the 20% darker color. If the color is saturated by 10%, you get
#A569FA. If the color is desaturated by 10%, the color
#A775EC is obtained.