The hex color #687eb5 is a dark color. The web-safe version is Hex
#6666CC. A complementary color is
#97814A. The grayscale version is
#898989. A 20% lighter version of the original color is
#9BB1E8, and Hex
#354B82 is the 20% darker color. If the color is saturated by 10%, you get
#657DB9. If the color is desaturated by 10%, the color
#6B7FB1 is obtained.