The hex color #1b4b64 is a dark color. The web-safe version is Hex
#333366. A complementary color is
#E4B49B. The grayscale version is
#434343. A 20% lighter version of the original color is
#4E7E97, and Hex
#001831 is the 20% darker color. If the color is saturated by 10%, you get
#174C67. If the color is desaturated by 10%, the color
#1F4A61 is obtained.