The hex color #31458c is a dark color. The web-safe version is Hex
#333399. A complementary color is
#CEBA73. The grayscale version is
#565656. A 20% lighter version of the original color is
#6478BF, and Hex
#001259 is the 20% darker color. If the color is saturated by 10%, you get
#2D4391. If the color is desaturated by 10%, the color
#354787 is obtained.