The hex color #647A8D is a dark color. The web-safe version is Hex
#666699. A complementary color is
#9B8572. The grayscale version is
#797979. A 20% lighter version of the original color is
#97ADC0, and Hex
#31475A is the 20% darker color. If the color is saturated by 10%, you get
#627A8F. If the color is desaturated by 10%, the color
#667A8B is obtained.