Colors in HTML can be specified either by using a hexadecimal notation or by typing
the name of the color. The hexadecimal notation uses a red-green-blue triplet, prefixed by
a hash mark (#). Hexadecimal means base-16 counting, so valid digits are 0 through 9
and A through F. Each value can range from 00 to FF, or 255 in decimal notation. All
in all this gives us 16 million colors available.
The named colors on the other hand includes only 16 names suggested by the HTML specification.
However, all major browsers recognize over a hundred different color names, so if you
know the name for a color you can most likely use it.