The hex color #1a283f is a dark color. The web-safe version is Hex
#333333. A complementary color is
#E5D7C0. The grayscale version is
#2B2B2B. A 20% lighter version of the original color is
#4D5B72, and Hex
#00000C is the 20% darker color. If the color is saturated by 10%, you get
#182841. If the color is desaturated by 10%, the color
#1C283D is obtained.