The hex color #646ece is a dark color. The web-safe version is Hex
#6666CC. A complementary color is
#9B9131. The grayscale version is
#8B8B8B. A 20% lighter version of the original color is
#97A1FF, and Hex
#313B9B is the 20% darker color. If the color is saturated by 10%, you get
#606BD5. If the color is desaturated by 10%, the color
#6871C7 is obtained.