A color value is a keyword or a numerical RGB specification.
RGB colors are given in one of four ways:
#rrggbb (e.g., #00cc00)
#rgb (e.g., #0c0)
rgb(x,x,x) where x is an integer between 0 and 255 inclusive (e.g., rgb(0,204,0))
rgb(y%,y%,y%) where y is a number between 0.0 and 100.0 inclusive (e.g., rgb(0%,80%,0%))
The 16 keywords are taken from the Windows VGA palette:
aqua, black, blue, fuchsia, gray, green, lime, maroon, navy, olive, purple, red, silver, teal, white, and yellow.
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Colors can be specified in HTML pages in two ways—by using a color name, or by using numbers to denote an RGB color value. An RGB color value consists of three two-digit hexadecimal numbers specifying the intensity of the corresponding color.
For example, the color value #FF0000 is rendered red because the red number is set to its highest value, FF (or 255 in decimal form).
Note While these color names might not be recognized by other browsers, the RGB color values should display accurately across browsers. When specifying color values for Web pages targeted to work across different browsers, use the RGB color values.
Full list of colour names (with their rrggbb colour code displayed as a 'tip') which can be used and are recognised in most browsers:
User-Defined System Colors
Microsoft® Windows® maintains a set of system colors for painting various parts of the display. In addition to the colors defined in the color table, as of Internet Explorer 4.0 these system colors may also be specified as color values in Web pages.
Users can set system colors for future Windows sessions using the Windows Control Panel. The following table illustrates the correspondence of these color names with the colors defined in the Control Panel.
Note The colors that do not correspond to any Control Panel colors can only be set programmatically using Windows APIs and cannot be defined by the user.