The hex color #1a3d3b is a dark color. The web-safe version is Hex
#333333. A complementary color is
#E5C2C4. The grayscale version is
#313131. A 20% lighter version of the original color is
#4D706E, and Hex
#000A08 is the 20% darker color. If the color is saturated by 10%, you get
#183E3C. If the color is desaturated by 10%, the color
#1C3C3A is obtained.