The hex color #3d505d is a dark color. The web-safe version is Hex
#336666. A complementary color is
#C2AFA2. The grayscale version is
#4E4E4E. A 20% lighter version of the original color is
#708390, and Hex
#0A1D2A is the 20% darker color. If the color is saturated by 10%, you get
#3B505F. If the color is desaturated by 10%, the color
#3F505C is obtained.