The hex color #3f788e is a dark color. The web-safe version is Hex
#336699. A complementary color is
#C08771. The grayscale version is
#6C6C6C. A 20% lighter version of the original color is
#72ABC1, and Hex
#0C455B is the 20% darker color. If the color is saturated by 10%, you get
#3A7991. If the color is desaturated by 10%, the color
#44778B is obtained.