Cyan (also called Aqua) is a color seen in the CMYK colors.
Cyan contains 0% red, 50% green, and 50% blue in RGB.
In CMYK, green contains 100% cyan, 0% magenta, 0% yellow, and 0% black.
Cyan is one of the safest web colors, listed as *0FF*, which is shorthand for its hex code (#00FFFF).
Here are some examples for using this color in CSS with Hex, RGB, HSL etc.