Web colors are colors used in designing web pages, and the methods for describing and specifying those colors. Colors may be specified as an RGB triplet or 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. Hexadecimal color codes begin with a hash (#).^[1][2] A color is specified according to the intensity of its red, green and blue components, each represented by eight bits. Thus, there are 24 bits used to specify a web color, and 16,777,216 colors that may be so specified.

The first versions of Mosaic and Netscape Navigator used the X11 color names as the basis for their color lists, as both started as X Window System applications.^[3]

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.^[4] 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.

Hex triplet[link]

A hex triplet is a six-digit, three-byte hexadecimal number used in HTML, CSS, SVG, 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. Thus web colors specify colors in the Truecolor (24-bit RGB) color scheme. The hex triplet is formed by concatenating three bytes in hexadecimal notation, in the following order:

Byte 1: red value (color type red)

Byte 2: green value (color type green)

Byte 3: blue value (color type blue)

For example, consider the color where the red/green/blue values are decimal numbers: red=36, green=104, blue=160 (a greyish-blue color). The decimal numbers 36, 104 and 160 are equivalent to the hexadecimal numbers 24, 68 and A0 respectively. The hex triplet is obtained by concatenating the 6 hexadecimal digits together, 2468A0 in this example.

Note that if any one of the three color values is less than 16 (decimal) or 10 (hex), it must be represented with a leading zero so that the triplet always has exactly six digits. For example, the decimal triplet 4, 8, 16 would be represented by the hex digits 04, 08, 10, forming the hex triplet 040810.

The number of colors that can be represented by this system is 256 × 256 × 256 = 16,777,216.

Shorthand hexadecimal form[link]

An abbreviated, three (hexadecimal) digits form is sometimes used.^[5] Expanding this form to the six-digit form is as simple as doubling each digit: 09C becomes 0099CC as presented on the following CSS example:

<source lang="css"> .threedigit { color: #09C; } .sixdigit { color: #0099CC; } /*same color as above*/ </source>

The three-digit form is described in the CSS specification, not in HTML. As a result, the three-digit form in an attribute other than "style" is not interpreted as a valid color in some browsers.

This shorthand form reduces the palette to 4,096 colors, equivalent of 12-bit color as opposed to 24-bit color using the whole six-digit form (16,777,216 colors). However, this limitation is often sufficient for text based documents.

Converting RGB to hexadecimal[link]

RGB values are usually given in the 0–255 range; if they are in the 0–1 range, the values are multiplied by 255 before conversion. This number divided by 16 (integer division; ignoring any remainder) gives us the first hexadecimal digit (between 0 and F, where the letters A to F represent the numbers 10 to 15. See hexadecimal for more details). The remainder gives us the second hexadecimal digit. For instance the RGB value 201 divides into 12 groups of 16, thus the first digit is C. A remainder of 9 gives us the hexadecimal number C9. This process is repeated for each of the three color values.

Conversion between number bases is a common feature of calculators, including both hand-held models and the software calculators bundled with most modern operating systems. Web-based tools specifically for converting color values are also available.^[6][7]

HTML color names[link]

The HTML 4.01 specification^[8] defines sixteen named colors, as follows (names are defined in this context to be case-insensitive):

These 16 were labelled as sRGB and included in the HTML 3.0 specification, which noted they were "the standard 16 colors supported with the Windows VGA palette."^[9]

X11 color names[link]

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 of colors. 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.

The list of colors actually shipped with the X11 product varies between implementations, and clashes with certain of the HTML names such as green. Furthermore, X11 colors are defined as simple RGB (hence, no particular color space), rather than sRGB. This means that the list of colors found in X11 (e.g. in /usr/lib/X11/rgb.txt) should not directly be used to choose colors for the web.^[10]

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. Note that this includes the common synonyms: aqua (HTML4/CSS 1.0 standard name) and cyan (common sRGB name), magenta (common sRGB name) and fuchsia (HTML4/CSS 1.0 standard name), gray (HTML4/CSS 1.0 standard name) and grey. ^[11][12]

Web-safe colors[link]

At one time many computer displays were only capable of displaying 256 colors. These may be dictated by the hardware or changeable by a "color table". When a color is found (e.g., in an image) that is not one available, a different one has to be used. This can be either using the closest color (fast) or dithering (slow, looks better).

There were various attempts to make a "standard" color palette. A set of colors was needed that could be shown without dithering on 256-color displays; the number 216 was chosen partly because computer operating systems customarily reserved sixteen to twenty colors for their own use; it was also selected because it allows exactly six equally-spaced shades of red, green, and blue (6 × 6 × 6 = 216), each from 00 to FF (including both limits).

The list of colors is often presented as if it has special properties that render them immune to dithering. In fact, on 256-color displays applications can set a palette of any selection of colors that they choose, dithering the rest. These colors were chosen specifically because they matched the palettes selected by the then leading browser applications. Fortunately, there were not radically different palettes in use in different popular browsers.^{[citation needed]}

"Web-safe" colors had a flaw in that, on systems such as X11 where the palette is shared between applications, smaller color cubes (5×5×5 or 4×4×4) were often allocated by browsers—thus, the "web safe" colors would actually dither on such systems. Better results were obtained by providing an image with a larger range of colors and allowing the browser to quantize the color space if needed, rather than suffer the quality loss of a double quantization.

As of 2011^[update], personal computers typically^[13] have 24-bit (TrueColor) and the use of "web-safe" colors has fallen into practical disuse. Even mobile devices have at least 16-bit color, driven by the inclusion of cameras on cellphones.^{[citation needed]}

The "web-safe" colors do not all have standard names, but each can be specified by an RGB triplet: each component (red, green, and blue) takes one of the six values from the following table (out of the 256 possible values available for each component in full 24-bit color).

The following table shows all of the "web-safe" colors, underlining the really-safe colors. (One shortcoming of the web-safe palette is its poor selection of light background colors.) The intensities at the low end of the range, especially the two darkest, are often hard to distinguish.

Color table[link]

In the table below, each color code listed is a short-hand for the RGB value; for example, code 609 is equivalent to RGB code 102-0-153 or HEX code #660099^[14].

Safest web colors[link]

Designers were often encouraged to stick to these 216 "web-safe" colors in their websites; however, 8-bit color displays were much more common when the 216-color palette was developed than they are now. David Lehn and Hadley Stern have since discovered that only 22 of the 216 colors in the web-safe palette are reliably displayed without inconsistent remapping on 16-bit computer displays. They called these 22 colors the "really safe" palette; it consists mainly of shades of green and yellow, as can be seen in the table above, where the "really safe" colors are underlined.^[15]

CSS colors[link]

The Cascading Style Sheets language defines the same number of named colors as the HTML 4 spec, namely the 16 listed previously. Additionally, CSS 2.1 adds the 'orange' color name to the list^[16]:

CSS 2, SVG and CSS 2.1 also allow web authors to use so-called system colors, which are color names whose values are taken from the operating system. This enables web authors to style their content in line with the operating system of the user agent.^[17] As of early 2004^[update], it appears that the CSS3 color module will once again drop these values, marking them deprecated, but this may change.^[18]

The developing CSS3 specification will also introduce HSL color space values to style sheets:

/* RGB model */
p { color: #F00 } /* #rgb */
p { color: #FF0000 } /* #rrggbb */
p { color: rgb(255, 0, 0) } /* integer range 0 - 255 */
p { color: rgb(100%, 0%, 0%) } /* float range 0.0% - 100.0% */

/* RGB with alpha channel, added to CSS3 */
p { color: rgba(255, 0, 0, 0.5) } /* 0.5 opacity, semi-transparent */

/* HSL model, added to CSS3 */
p { color: hsl(0, 100%, 50%) } /* red */
p { color: hsl(120, 100%, 50%) } /* green */
p { color: hsl(120, 100%, 25%) } /* dark green */
p { color: hsl(120, 100%, 75%) } /* light green */
p { color: hsl(120, 50%, 50%) } /* pastel green */

/* HSL model with alpha channel */
p { color: hsla(120, 100%, 50%, 1) } /* green */
p { color: hsla(120, 100%, 50%, 0.5) } /* semi-transparent green */
p { color: hsla(120, 100%, 50%, 0.1) } /* very transparent green */

Accessibility[link]

Some browsers and devices do not support colors. For these blind and colorblind users, Web content depending on colors can be unusable or difficult to use. Both foreground and background color should be modified to avoid black on black effects.^[19] Similarly, most browsers show links as shades of blue by default; therefore, dark background colors, such as blue or navy, do not display well for such links.

See also[link]

	Color portal
	Computer graphics portal

• Color tool
• List of colors
• List of color palettes
• CIE 1931 XYZ color space
• CIE L*a*b* color space
• Wide Gamut RGB color space
• ProPhoto RGB
• Adobe RGB color space
• scRGB
• sRGB
• RGB color space

References[link]

External links[link]

• 4,096 Web-Safe Colors
• CSS2.1 Color Specification
• Sortable Table of X11 Colors
• Web colors at the Open Directory Project
• Online Color Picker with Web Colors
• X11/browser colors, with closest web-safe equivalents

The word asshole, a variant of arsehole, which is still prevalent in British and Australian English, is a vulgar to describe the anus, often pejoratively used to refer to people.

History[link]

The word arse in English derives from the Germanic root *arsaz, which originated from the Proto-Indo-European root *ors — meaning buttocks or backside.^[1] The combined form arsehole is first attested from 1500 in its literal use to refer to the anus. The metaphorical use of the word to refer to the worst place in a region, e.g., "the arsehole of the world") is first attested in print in 1865; the use to refer to a contemptible person is first attested in 1933.^[2] In the ninth chapter of his 1945 autobiography, Black Boy, Richard Wright quotes a snippet of verse that uses the term: "All these white folks dressed so fine / Their ass-holes smell just like mine ...". Its first appearance as an insult term in a newspaper indexed by Google News is in 1965.^[3] As with other vulgarities, these uses of the word may have been common in oral speech for some time before their first print appearances. By the 1970s, Hustler magazine featured people they did not like as "Asshole of the Month."^[4] In 1972, Jonathan Richman's Modern Lovers recorded his song "Pablo Picasso," which includes the line "Pablo Picasso was never called an asshole."

Until the early 1990s, the word was considered one of a number of words that could not be uttered on commercial television in the United States. Comedian Andrew Dice Clay caused a major shock when he uttered the word during a televised MTV awards show in 1989.^[5] However, there were PG-13 and R rated films in the 1980s that featured use of the word, such as the R-rated The Terminator (1984), the PG-13-rated National Lampoon's Christmas Vacation (1989), and the PG-rated Back to the Future (1985). By 1994, however, vulgarity had become more acceptable, and the word was featured in dialog on the long-running television series NYPD Blue, though it has yet to become anything close to commonplace on network TV. In some broadcast edits (such as the syndication airings of South Park), the word is partially bleeped out — ironically, as "assh—", with the profane half of the word intact.

Semantics[link]

The word is mainly used as a vulgarity, generally to describe people who are viewed as stupid or incompetent or detestable.^[6]

This word or its literal translation is found in colloquial speech in a number of cultures (in both English and other languages).^[7] This is because it describes an organ of elimination that is considered a taboo region (since it belongs to the intimate parts) of the body in many societies.^[8]

The English word ass (meaning donkey, a cognate of its zoological name Equus asinus) may also be used as a term of contempt, referring to a silly or stupid person. In the United States, and, to a lesser degree, in Canada, the words arse and ass have become synonymous; however, in the rest of the English-speaking world, ass still only refers to the donkey, rather than the arse (buttocks). It is worth noting that speakers of some varieties of English "drop their Rs" before consonants, leading to a pronunciation of arse that is quite similar to ass.^[9]

Political usage[link]

In 2000, during a Labor Day event, then candidate George W. Bush made an off-hand remark to his running mate, Dick Cheney, that New York Times reporter Adam Clymer was a "major league asshole." The gaffe was caught on microphone and led to a political advertisement chiding Bush for "using expletives ... in front of a crowd of families," produced for Democratic opponent Al Gore.^[10]

In February 2004, American media reported that during a rally of supporters, Venezuelan President Hugo Chavez called Bush "an asshole" for believing his aides in supporting a coup against Chavez in 2002.^[11] The word in the original Spanish was "pendejo", and in news coverage the word was widely, though incorrectly, translated as "asshole"; the meaning of the word varies substantially in Latin America, and in Venezuela its meaning is closer to "fool".^[12] The following year, in September, Nightline host Ted Koppel said to Chavez on national television, "I'm going to perhaps shock you a little, but these are your words. You called President Bush an asshole," to which Chavez replied, "I've said various things about him. I don't know if I actually used that word."^[13]

See also[link]

• Arse
• The No Asshole Rule
• Sexual Slang
• Profanity

References[link]