Web colors are colors used in designing web pages, and the methods for describing and specifying those colors.

Authors of web pages have a variety of options available for specifying colors for elements of web documents. Colors may be specified as an RGB triplet in hexadecimal format (a hex triplet); they may also be specified according to their common English names in some cases. Often a color tool or other graphics software is used to generate color values.

The RGB color model or RBG color standard is an additive model in which red, green and blue are combined in various ways to reproduce other colors

In mathematics and computer science, hexadecimal, base-16, or simply hex, is a numeral system with a radix, or base, of 16, usually written using the symbols 0–9 and A–F, or a–f.

The first versions of Mosaic and Netscape Navigator used the X11 color names as the basis for their color lists, as both started as Xwindow System applications.

In computing, on the X Window System, X11 color names are represented in a simple text file, which maps certain strings to RGB color values and the X Window System (commonly X11 or X) is a networking and display protocol which provides windowing on bitmap displays.

Web colors have an unambiguous colorimetric definition, SRGB, which relates the chromaticities of a particular phosphor set, a given transfer curve, adaptive whitepoint, and viewing conditions. These have been chosen to be similar to many real-world monitors and viewing conditions, so that even without color management rendering is fairly close to the specified values. However, user agents vary in the fidelity with which they represent the specified colors. More advanced user agents use color management to provide better color fidelity; this is particularly important for Web to print applications.

sRGB color space is a standard RGB (Red, Green, Blue) color space created cooperatively by HP and Microsoft for use on monitors, printers, and the Internet

A hex triplet is a six-digit, three-byte hexadecimal number used in HTML and CSS, and other computing applications, to represent colors. The bytes represent the red, green and blue components of the color. One byte represents a number in the range 00 to FF in hexadecimal notation, or 0 to 255 in decimal notation. This represents the least (0) to the most (255) intensity of each of the color components. The hex triplet is formed by concatenating three bytes in hexadecimal notation, in the following order:

            Byte 1: red value              Byte 2: green value               Byte 3: blue value

The number of colors that can be represented by this system is

Converting RGB to Hexadecimal

Converting a decimal RGB value to a hexadecimal value is fairly straightforward. . Most modern operating system have a built-in calculator to perform conversions between number bases; this can also be done with some calculators. This task can also be carried out with various Internet resources, for instance the website http://www.telacommunications.com/nutshell/rgbform.htm

 The HTML 4.01 specification defines sixteen named colors, These 16 were also specified as sRGB and included in the HTML 3.0 specification.These colors were originally picked as being the standard 16 colors supported with the Windows VGA palette

It should be mentioned that all color values from #000000 - #FFFFFF (16,777,216 colors) are valid.

X11 Color Names

A number of colors are defined by web browsers. As of 2005 all modern general-use browsers support the full list. Many of these colors are from the list of X11 color names distributed with the X Window System..