The hex color #183a5c is a dark color. The web-safe version is Hex
#003366. A complementary color is
#E7C5A3. The grayscale version is
#3A3A3A. A 20% lighter version of the original color is
#4B6D8F, and Hex
#000729 is the 20% darker color. If the color is saturated by 10%, you get
#153A5F. If the color is desaturated by 10%, the color
#1B3A59 is obtained.