The hex color #181b51 is a dark color. The web-safe version is Hex
#003366. A complementary color is
#E7E4AE. The grayscale version is
#2C2C2C. A 20% lighter version of the original color is
#4B4E84, and Hex
#00001E is the 20% darker color. If the color is saturated by 10%, you get
#161955. If the color is desaturated by 10%, the color
#1A1D4D is obtained.