The hex color #2d3f5c is a dark color. The web-safe version is Hex
#333366. A complementary color is
#D2C0A3. The grayscale version is
#434343. A 20% lighter version of the original color is
#60728F, and Hex
#000C29 is the 20% darker color. If the color is saturated by 10%, you get
#2B3F5F. If the color is desaturated by 10%, the color
#2F3F59 is obtained.