Because browsers appear on almost any known Operating
System there is a problem with displaying the proper colors. Not
all systems can handle 16,8 million colors (ie. 24 bit) for example.
That's why there is a predefined palette of 196 colors, called the
Browser Safe Color Palette. To make sure the color of your choice
appears as the same color on all computers.
Colors can be respresented in terms like "blue"
and "red" and "cyan", but
also in red-green-blue pairs. These values are represented in hex-values.
For example #000000 will produce Black and #FF0000
will produce red. The pairs are create by the hex values of red,
green and blue as such: #RRGGBB.
You use these values for example (including the
"#"-character!) for defining the background
color, font color, table color, etc.
In the table below you will see these color-codes
and their appearance.