The hex color #3f779c is a dark color. The web-safe version is Hex
#336699. A complementary color is
#C08863. The grayscale version is
#717171. A 20% lighter version of the original color is
#72AACF, and Hex
#0C4469 is the 20% darker color. If the color is saturated by 10%, you get
#3A78A0. If the color is desaturated by 10%, the color
#447698 is obtained.