The hex color #31538c is a dark color. The web-safe version is Hex
#336699. A complementary color is
#CEAC73. The grayscale version is
#5B5B5B. A 20% lighter version of the original color is
#6486BF, and Hex
#002059 is the 20% darker color. If the color is saturated by 10%, you get
#2D5291. If the color is desaturated by 10%, the color
#355487 is obtained.