The hex color #21c0fb is a light color. The web-safe version is Hex
#33CCFF. A complementary color is
#DE3F04. The grayscale version is
#9F9F9F. A 20% lighter version of the original color is
#54F3FF, and Hex
#008DC8 is the 20% darker color. If the color is saturated by 10%, you get
#14C3FF. If the color is desaturated by 10%, the color
#2EBDF2 is obtained.