The hex color #3f7b92 is a dark color. The web-safe version is Hex
#336699. A complementary color is
#C0846D. The grayscale version is
#6F6F6F. A 20% lighter version of the original color is
#72AEC5, and Hex
#0C485F is the 20% darker color. If the color is saturated by 10%, you get
#3A7C96. If the color is desaturated by 10%, the color
#447A8E is obtained.