Some years ago, computers support maximum 256 different colors, a list of 216 Web Safe Colors was suggested as a Web Standard
The 216 web safe color palette was created to ensure that all computer would display the colors correctly when running a 256 color palette.
This is not important now, since most computer can display millions of different colors.Any way here is the list web safe colors:
The World Wide Web Consortium has listed 16 valid color names for HTML and CSS they are: AQUA, BLACK, BLUE, FUCHSIA, GRAY, GREEN, LIME, MAROON, NAVY, OLIVE, PURPLE, RED, SILVER, TEAL, WHITE and YELLOW. To use other colors in a website, web builders must specify their HEX value.