The hex color #317f8c is a dark color. The web-safe version is Hex
#336699. A complementary color is
#CE8073. The grayscale version is
#696969. A 20% lighter version of the original color is
#64B2BF, and Hex
#004C59 is the 20% darker color. If the color is saturated by 10%, you get
#2B818F. If the color is desaturated by 10%, the color
#377D89 is obtained.