The hex color #00c4e9 is a light color. The web-safe version is Hex
#00CCFF. A complementary color is
#FF3B16. The grayscale version is
#8F8F8F. A 20% lighter version of the original color is
#33F7FF, and Hex
#0091B6 is the 20% darker color. If the color is saturated by 10%, you get
#00C9F2. If the color is desaturated by 10%, the color
#0EBFE0 is obtained.