A few years ago computers were only capable of
displaying 256 colors, hence the web safe colors.
With today's computers being able to display 16 million
colors, the web safe colors are not really an issue.
The numbers you see on each color is the hexadecimal
value of that color. The numbers represent the
value for Red, Green and Blue. Each color has 256
possibilities (hex value 00-FF) , so 256 X 256 X 256=
16,777,216 possible combinations of colors.