The hex color #5181bb is a dark color. The web-safe version is Hex
#6699CC. A complementary color is
#AE7E44. The grayscale version is
#848484. A 20% lighter version of the original color is
#84B4EE, and Hex
#1E4E88 is the 20% darker color. If the color is saturated by 10%, you get
#4C81C0. If the color is desaturated by 10%, the color
#5681B6 is obtained.