The hex color #1a3f1f is a dark color. The web-safe version is Hex
#333333. A complementary color is
#E5C0E0. The grayscale version is
#282828. A 20% lighter version of the original color is
#4D7252, and Hex
#000C00 is the 20% darker color. If the color is saturated by 10%, you get
#19411E. If the color is desaturated by 10%, the color
#1B3D20 is obtained.