The hex color #3d6b6d is a dark color. The web-safe version is Hex
#336666. A complementary color is
#C29492. The grayscale version is
#5C5C5C. A 20% lighter version of the original color is
#709EA0, and Hex
#0A383A is the 20% darker color. If the color is saturated by 10%, you get
#3A6C6F. If the color is desaturated by 10%, the color
#406A6B is obtained.