The hex color #64699c is a dark color. The web-safe version is Hex
#666699. A complementary color is
#9B9663. The grayscale version is
#787878. A 20% lighter version of the original color is
#979CCF, and Hex
#313669 is the 20% darker color. If the color is saturated by 10%, you get
#6267A0. If the color is desaturated by 10%, the color
#666B98 is obtained.