The hex color #3C99F3 is a light color. The web-safe version is Hex
#3399FF. A complementary color is
#C3660C. The grayscale version is
#989898. A 20% lighter version of the original color is
#6FCCFF, and Hex
#0966C0 is the 20% darker color. If the color is saturated by 10%, you get
#3399FC. If the color is desaturated by 10%, the color
#4599EA is obtained.