The hex color #687df0 is a light color. The web-safe version is Hex
#6666FF. A complementary color is
#97820F. The grayscale version is
#9C9C9C. A 20% lighter version of the original color is
#9BB0FF, and Hex
#354ABD is the 20% darker color. If the color is saturated by 10%, you get
#637AF8. If the color is desaturated by 10%, the color
#6D80E8 is obtained.