The hex color #687b74 is a dark color. The web-safe version is Hex
#666666. A complementary color is
#97848B. The grayscale version is
#727272. A 20% lighter version of the original color is
#9BAEA7, and Hex
#354841 is the 20% darker color. If the color is saturated by 10%, you get
#677C74. If the color is desaturated by 10%, the color
#697A74 is obtained.