The hex color #1a3f5d is a dark color. The web-safe version is Hex
#333366. A complementary color is
#E5C0A2. The grayscale version is
#3D3D3D. A 20% lighter version of the original color is
#4D7290, and Hex
#000C2A is the 20% darker color. If the color is saturated by 10%, you get
#173F60. If the color is desaturated by 10%, the color
#1D3F5A is obtained.