The hex color #1b738f is a dark color. The web-safe version is Hex
#336699. A complementary color is
#E48C70. The grayscale version is
#5F5F5F. A 20% lighter version of the original color is
#4EA6C2, and Hex
#00405C is the 20% darker color. If the color is saturated by 10%, you get
#147594. If the color is desaturated by 10%, the color
#22718A is obtained.