The hex color #687ee6 is a light color. The web-safe version is Hex
#6666FF. A complementary color is
#978119. The grayscale version is
#999999. A 20% lighter version of the original color is
#9BB1FF, and Hex
#354BB3 is the 20% darker color. If the color is saturated by 10%, you get
#637BEE. If the color is desaturated by 10%, the color
#6D81DE is obtained.