The hex color #6643cc is a dark color. The web-safe version is Hex
#6633CC. A complementary color is
#99BC33. The grayscale version is
#7C7C7C. A 20% lighter version of the original color is
#9976FF, and Hex
#331099 is the 20% darker color. If the color is saturated by 10%, you get
#643DD4. If the color is desaturated by 10%, the color
#6849C4 is obtained.