The hex color #687F7B is a dark color. The web-safe version is Hex
#666666. A complementary color is
#978084. The grayscale version is
#767676. A 20% lighter version of the original color is
#9BB2AE, and Hex
#354C48 is the 20% darker color. If the color is saturated by 10%, you get
#67807C. If the color is desaturated by 10%, the color
#697E7B is obtained.