The hex color #1b5d6f is a dark color. The web-safe version is Hex
#336666. A complementary color is
#E4A290. The grayscale version is
#4D4D4D. A 20% lighter version of the original color is
#4E90A2, and Hex
#002A3C is the 20% darker color. If the color is saturated by 10%, you get
#165F72. If the color is desaturated by 10%, the color
#205B6C is obtained.