The hex color #639cce is a light color. The web-safe version is Hex
#6699CC. A complementary color is
#9C6331. The grayscale version is
#9A9A9A. A 20% lighter version of the original color is
#96CFFF, and Hex
#30699B is the 20% darker color. If the color is saturated by 10%, you get
#5E9CD3. If the color is desaturated by 10%, the color
#689CC9 is obtained.