Help:Color Codes

Wikitext can take advantage of various different method of specifying colors, but the most common method is by name or hex code.

HTML color names
The HTML 4.01 specification defines sixteen named colors, as follows (names are defined in this context to be case-insensitive; the table is alphabetically ordered):

These 16 were also specified as sRGB and included in the HTML 3.0 specification

X11 color names
In addition, a number of colors are defined by web browsers. A particular browser may not recognize all of these colors, but 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. These colors were standardized by SVG 1.0, and are accepted by SVG Full user agents. They are not part of SVG Tiny.

Almost the exact same color names are used in .NET Framework, in the KnownColor and Color enumerations. The only color difference is DarkSeaGreen which is defined as 8F,BC,8B (instead of 8F,BC,8F).

The list of web "X11 colors" from the CSS3 specification, along with their hexadecimal and decimal equivalents, is shown below, compare the alphabetical lists in the W3C standards.