X11 color names explained

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. It was traditionally shipped with every X11 installation, hence the name, and is usually located in ''<X11root>''/lib/X11/rgb.txt. The web colors list is descended from it but differs for certain color names.[1]

Color names are not standardized by Xlib or the X11 protocol. The list does not show continuity either in selected color values or in color names, and some color triplets have multiple names. Despite this, graphic designers and others got used to them, making it practically impossible to introduce a different list. In earlier releases of X11 (prior to the introduction of Xcms), server implementors were encouraged to modify the RGB values in the reference color database to account for gamma correction.[2]

As of X.Org Release 7.4 rgb.txt is no longer included in the roll up release,[3] and the list is built directly into the server.[4] The optional module xorg/app/rgb contains the stand-alone rgb.txt file.

The list first shipped with X10 release 3 (X10R3) on 7 June 1986, having been checked into RCS by Jim Gettys in 1985.[5] The same list was in X11R1 on 18 September 1987. Approximately the full list as is available today shipped with X11R4 on 29 January 1989, with substantial additions by Paul Ravelling (who added colors based on Sinclair Paints samples), John C. Thomas (who added colors based on a set of 72 Crayola crayons he had on hand) and Jim Fulton (who reconciled contributions to produce the X11R4 list). The project was running DEC VT240 terminals at the time, so would have worked to that device.[6]

In some applications multipart names are written with spaces, in others joined together, often in camel case. They are usually matched insensitive of case and the X Server source code contains spaced aliases for most entries; this article uses spaces and uppercase initials except where variants with spaces are not specified in the actual code.

Clashes between web and X11 colors in the CSS color scheme

The first versions of Mosaic and Netscape Navigator used the X11 colors as the basis for the web colors list, as both were originally X applications. The W3C specifications SVG and CSS level 3 module Color eventually adopted the X11 list with some changes.[7] The present W3C list is a superset of the 16 "VGA colors" defined in HTML 3.2 and CSS level 1.

One notable difference between X11 and W3C is the case of "Gray" and its variants. In HTML, "Gray" is specifically reserved for the 128 triplet (50% gray) . However, in X11, "gray" was assigned to the 190 triplet (74.5%), which is close to W3C "Silver" at 192 (75.3%), and had "Light Gray" at 211 (83%) and "Dark Gray" at 169 (66%) counterparts. As a result, the combined CSS 3.0 color list that prevails on the web today produces "Dark Gray" as a significantly lighter tone than plain "Gray", because "Dark Gray" was descended from X11 – for it did not exist in HTML nor CSS level 1[8] – while "Gray" was descended from HTML. Even in the current draft for CSS 4.0, dark gray continues to be a lighter shade than gray.[9] Some browsers such as Netscape Navigator insisted on an "a" in any "Gray" except for "Light Grey".

Recent X releases (since 2014, xorg-rgb version 1.0.6)[10] also support the W3C definitions. In X11, the original definitions have been preserved (so "Dark Gray" remains a darker shade of "Gray"), but for every conflicting name pair, "Web" and additional "X11" prefixes have been added to ease disambiguation after the merger. The "X11" prefix is an alias for the non-prefixed version, i.e. "X11 Gray" = "Gray" ≠ "Web Gray". The W3C also defined a color that is equal to X11's "Green", but called it "Lime". In X11, this is simply called "Lime", as no such name existed before. It aliases to "Green", i.e. "Lime" = "Green" = "X11 Green" ≠ "Web Green".

Color names with clashing definitions
Color nameX11 colorW3C color
BlueSampleSampleHex Red Green Blue
Gray
  1. BEBEBE
75% 75% 75%  
  1. 808080
50% 50% 50%
Green
  1. 00FF00
0% 100% 0%  
  1. 008000
0% 50% 0%
Maroon
  1. B03060
69% 19% 38%  
  1. 800000
50% 0% 0%
Purple
  1. A020F0
63% 13% 94%  
  1. 800080
50% 0% 50%
Colors with multiple names
W3C nameColorX11 name
BlueSample
Lime[11]
  1. 00FF00
0% 100% 0% Green
Fuchsia
  1. FF00FF
100% 0% 100% Magenta
Aqua
  1. 00FFFF
0% 100% 100% Cyan

Color name chart

The following chart presents the standardized X11 color names from the X.org source code.[12] The list of names accepted by browsers following W3C standards[13] slightly differs as explained above. The table does not show numbered gray and brightness variants as described below. Actual rgb.txt files and other color databases or palettes may differ since they are freely editable by vendors and users. The table shows component values in several notations of the RGB color space, i.e. RGB (non-linear), HSL and HSV, conversions are done assuming sRGB color space.

Color variations

Shades of gray

The complete rgb.txt defines 101 shades from 'Gray0' (black) up to 'Gray100' (white) in addition to 'Gray' and its variants listed above. The shades are apparently defined by the formula Gray''N'' := round(''N''% × 255) resulting in e.g. 'Gray96', which happens to be the same as 'White Smoke'. Similarly 'Dim Gray' is the same as 'Gray41' .

On the other hand, 'Gray' lies between 'Gray74' and 'Gray75' ; 'Dark Gray' is not the same as 'Gray66' ; and 'Light Gray' is not the same as 'Gray83' .

These shades are not included in W3C specifications, although drafts for level 4 of the CSS Color module include a similar function gray.They are still coded without 'Grey' alternatives, but with no space before the digit.

Numbered variants

For 78 colors (not counting grays), rgb.txt offers four variants "color1", "color2", "color3", and "color4", with "color1" sometimes corresponding to "color", so e.g. "Snow1" is the same as "Snow". Unlike base colors, e.g. cadet blue and CadetBlue, these are only coded without spaces, e.g. CadetBlue3. These variations are neither supported by popular browsers nor adopted by W3C standards. Whether or not a certain color has such variants seems random.

If "color1" is not the same as "color, the base color is usually darker. That means its brightness in HSB color notation is less than 100%; about 30 of the base colors are fully bright. The four variants (1...4) have rounded brightness values of 100%, 93%, 80% and 55%, respectively. Their hue and saturation are usually the same except for rounding. In some cases they differ from the base color, though, which may indicate that these variants were specified with alternate definitions of the bases in mind, i.e. their values were adapted to a certain monitor which was commonly done by vendors until the 1990s.

The fixed brightness settings correspond closely to these formulae to determine the RGB values:

''color''1 := ''color'' × 100%

''color''2 := ''color''1 × 93.2%

''color''3 := ''color''1 × 80.4%

''color''4 := ''color''1 × 54.8%

Examples:

Brightness!style="border-left:1em solid transparent"
StandardVariant 1 (100%)Variant 2 (93.2%)Variant 3 (80.4%)Variant 4 (54.8%)
Antique White34±1° 14% 98%#FAEBD7#FFEFDB#EEDFCC#CDC0B0#8B8378
Aquamarine160° 50% 100%#7FFFD4#76EEC6#66CDAA#458B74
Azure180° 6% 100%#F0FFFF#E0EEEE#C1CDCD#838B8B
Bisque33±1° 23% 100%#FFE4C4#EED5B7#CDB79E#8B7D6B
Blue240° 100% 100%#0000FF#0000EE#0000CD#00008B
Brown75% 65%#A52A2A#FF4040#EE3B3B#CD3333#8B2323
Burlywood34° 39% 87%#DEB887#FFD39B#EEC591#CDAA7D#8B7355
Cadet Blue182–186° >40% 63%#5F9EA0#98F5FF#8EE5EE#7AC5CD#53868B
Chartreuse90° 100% 100%#7FFF00#76EE00#66CD00#458B00
Chocolate25° 86% 82%#D2691E#FF7F24#EE7621#CD661D#8B4513
Coral10°/16° 66%/69% 100%#FF7F50#FF7256#EE6A50#CD5B45#8B3E2F
Cornsilk48–51° 14% 100%#FFF8DC#EEE8CD#CDC8B1#8B8878
Cyan180° 100% 100%#00FFFF#00EEEE#00CDCD#008B8B
Dark Goldenrod43° 94% 72%#B8860B#FFB90F#EEAD0E#CD950C#8B6508
Dark Olive Green82° 56% 42%#556B2F#CAFF70#BCEE68#A2CD5A#6E8B3D
Dark Orange30°/33° 100% 100%#FF8C00#FF7F00#EE7600#CD6600#8B4500
Dark Orchid280° 76% 80%#9932CC#BF3EFF#B23AEE#9A32CD#68228B
Dark Sea Green120° 24% 74%#8FBC8F#C1FFC1#B4EEB4#9BCD9B#698B69
Dark Slate Gray180° 41% 31%#2F4F4F#97FFFF#8DEEEE#79CDCD#528B8B
Deep Pink328° 92% 100%#FF1493#EE1289#CD1076#8B0A50
Deep Sky Blue195° 100% 100%#00BFFF#00B2EE#009ACD#00688B
Dodger Blue210° 88% 100%#1E90FF#1C86EE#1874CD#104E8B
Firebrick81% 70%#B22222#FF3030#EE2C2C#CD2626#8B1A1A
Gold51° 100% 100%#FFD700#EEC900#CDAD00#8B7500
Goldenrod43° 86% 86%#DAA520#FFC125#EEB422#CD9B1D#8B6914
Green120° 100% 100%#00FF00#00EE00#00CD00#008B00
Honeydew120° 6% 100%#F0FFF0#E0EEE0#C1CDC1#838B83
Hot Pink330–334° 53–59% 100%#FF69B4#FF6EB4#EE6AA7#CD6090#8B3A62
Indian Red55–59% 80%#CD5C5C#FF6A6A#EE6363#CD5555#8B3A3A
Ivory60° 6% 100%#FFFFF0#EEEEE0#CDCDC1#8B8B83
Khaki55° 44% 100%#F0E68C#FFF68F#EEE685#CDC673#8B864E
Lavender Blush339±1° 6% 100%#FFF0F5#EEE0E5#CDC1C5#8B8386
Lemon Chiffon54° 20% 100%#FFFACD#EEE9BF#CDC9A5#8B8970
Light Blue195° 25% 90%#ADD8E6#BFEFFF#B2DFEE#9AC0CD#68838B
Light Cyan180° 12% 100%#E0FFFF#D1EEEE#B4CDCD#7A8B8B
Light Goldenrod50° 45% 93%#EEDD82#FFEC8B#EEDC82#CDBE70#8B814C
Light Pink351°/352° 29%/32% 100%#FFB6C1#FFAEB9#EEA2AD#CD8C95#8B5F65
Light Salmon17° 52% 100%#FFA07A#EE9572#CD8162#8B5742
Light Sky Blue202°/203° 31%/46% 100%#87CEFA#B0E2FF#A4D3EE#8DB6CD#607B8B
Light Steel Blue214° 21% 87%#B0C4DE#CAE1FF#BCD2EE#A2B5CD#6E7B8B
Light Yellow60° 12% 100%#FFFFE0#EEEED1#CDCDB4#8B8B7A
Magenta300° 100% 100%#FF00FF#EE00EE#CD00CD#8B008B
Maroon322°/338° 73%/80% 69%#B03060#FF34B3#EE30A7#CD2990#8B1C62
Medium Orchid288° 60% 83%#BA55D3#E066FF#D15FEE#B452CD#7A378B
Medium Purple260° 49% 86%#9370DB#AB82FF#9F79EE#8968CD#5D478B
Misty Rose12% 100%#FFE4E1#EED5D2#CDB7B5#8B7D7B
Navajo White36° 32% 100%#FFDEAD#EECFA1#CDB38B#8B795E
Olive Drab80° 76% 56%#6B8E23#C0FF3E#B3EE3A#9ACD32#698B22
Orange39° 100% 100%#FFA500#EE9A00#CD8500#8B5A00
Orange Red16° 100% 100%#FF4500#EE4000#CD3700#8B2500
Orchid302° 49% 86%#DA70D6#FF83FA#EE7AE9#CD69C9#8B4789
Pale Green120° 40% 98%#98FB98#9AFF9A#90EE90#7CCD7C#548B54
Pale Turquoise180° 27% 93%#AFEEEE#BBFFFF#AEEEEE#96CDCD#668B8B
Pale Violet Red340° 49% 86%#DB7093#FF82AB#EE799F#CD6889#8B475D
Peach Puff28° 27% 100%#FFDAB9#EECBAD#CDAF95#8B7765
Pink347°/350° 25%/29% 100%#FFC0CB#FFB5C5#EEA9B8#CD919E#8B636C
Plum300° 27% 87%#DDA0DD#FFBBFF#EEAEEE#CD96CD#8B668B
Purple271°/277° 81%/87% 94%#A020F0#9B30FF#912CEE#7D26CD#551A8B
Red100% 100%#FF0000#EE0000#CD0000#8B0000
Rosy Brown24% 74%#BC8F8F#FFC1C1#EEB4B4#CD9B9B#8B6969
Royal Blue225° 72% 88%#4169E1#4876FF#436EEE#3A5FCD#27408B
Salmon6°/14° 54%/59% 98%#FA8072#FF8C69#EE8262#CD7054#8B4C39
Sea Green147° 67% 55%#2E8B57#54FF9F#4EEE94#43CD80#2E8B57
Seashell26±1° 7% 100%#FFF5EE#EEE5DE#CDC5BF#8B8682
Sienna19° 72% 63%#A0522D#FF8247#EE7942#CD6839#8B4726
Sky Blue197°/205° 43%/47% 92%#87CEEB#87CEFF#7EC0EE#6CA6CD#4A708B
Slate Blue248° 57% 80%#6A5ACD#836FFF#7A67EE#6959CD#473C8B
Slate Gray210° 22% 57%#708090#C6E2FF#B9D3EE#9FB6CD#6C7B8B
Snow2% 100%#FFFAFA#EEE9E9#CDC9C9#8B8989
Spring Green150° 100% 100%#00FF7F#00EE76#00CD66#008B45
Steel Blue207° 61% 71%#4682B4#63B8FF#5CACEE#4F94CD#36648B
Tan30°/34° 33%/69% 82%#D2B48C#FFA54F#EE9A49#CD853F#8B5A2B
Thistle300° 12% 85%#D8BFD8#FFE1FF#EED2EE#CDB5CD#8B7B8B
Tomato72% 100%#FF6347#EE5C42#CD4F39#8B3626
Turquoise174°/182° 71%/100% 88%#40E0D0#00F5FF#00E5EE#00C5CD#00868B
Violet Red322°/333° 76%/85% 82%#D02090#FF3E96#EE3A8C#CD3278#8B2252
Wheat39° 27% 96%#F5DEB3#FFE7BA#EED8AE#CDBA96#8B7E66
Yellow60° 100% 100%#FFFF00#EEEE00#CDCD00#8B8B00

Prefixed variants

Some color names appear to be brightness or saturation modifications of others because they bear prefixes such as Dark, Light, Medium, Pale or Deep, but there is no systematic variation apparent. Several sets, however, feature a Dark variant with 55% brightness and some have their Medium at about 80%.

"Light Goldenrod Yellow" and "Dark Olive Green" are special, because there are no corresponding color entries without Dark and Light prefixes.

Base !!style="border-left:1em solid transparent"
Pale !Light Medium Dark Deep other
Aquamarine100% bright80% bright
Blue100% brightcomplex80% bright55% bright
Slate Blue80% bright100% bright93% bright55% bright
Sky Bluecomplex100% saturated and bright
Steel Bluecomplex
Coralcomplex
Cyan100% bright, 50% light94% light55% bright
Goldenrodcomplexcomplexcomplexcomplex
Gray75% bright83% bright66% bright41% bright
Slate Gray57% bright60% brightcomplex
Green100% bright98% bright93% bright39% bright50% bright
Olive Greencomplexcomplex
Sea Green55% brightcomplex70% brightcomplex
Spring Green100% brightcomplex
Khaki94% bright74% bright
Magenta100% bright55% bright
Orange39° hue<--65% green-->33° hue<--55% green-->
Orchidcomplexcomplex
Pink88% light86% lightcomplexcomplex
Purplecomplexcomplex
Violet Red47% light, 82% brightcomplex43% light, 78% bright
Red100% bright55% bright
Salmoncomplexcomplex
Turquoisecomplexcomplexcomplex
Violetcomplex
Yellow50% light94% light

Nuances with different hue

Several groups of colors share the same lightness or brightness and saturation. These nuances differ only by hue.

100%/25%: 0° (Web) Maroon, 60° Olive, 120° Green, 180° Teal, 240° Navy (Blue), 300° (Web) Purple
  • 100%/27%: 0° Dark Red, 180° Dark Cyan, 240° Dark Blue, 300° Dark Magenta
  • 100%/41%: 181° Dark Turquoise, 282° Dark Violet
  • 100%/49%: 90° Lawn Green, 157° Medium Spring Green
  • 61%/50%: 80° Yellow Green, 120° Lime Green, 280° Dark Orchid
  • 100%/50%: 0° Red, 16° Orange Red, 33° Dark Orange, 39° Orange, 51° Gold, 60° Yellow, 90° Chartreuse, 120° (Lime) Green, 150° Spring Green, 180° Aqua / Cyan, 195° Deep Sky Blue, 240° Blue, 300° Fuchsia / Magenta
  • 25%/65%: 0° Rosy Brown, 120° Dark Sea Green
  • 59–60%/65%: 260° Medium Purple, 302° Orchid, 340° Pale Violet Red
  • 100%/86%: 38° Moccasin, 351° Light Pink
  • 100%/90%: 36° Blanched Almond, 54° Lemon Chiffon
  • 67%/94%: 30° Linen, 240° Lavender
  • 100%/94%: 6° Misty Rose, 60° Light Yellow, 180° Light Cyan
  • 100%/97%: 25° Seashell, 40° Floral White, 60° Ivory, 120° Honeydew, 180° Azure, 208° Alice Blue, 340° Lavender Blush
  • 100%/99%: 0° Snow, 240° Ghost White
  • Tints and shades with different lightness

    Several groups of colors share the same hue and HSL saturation. Tints are lighter than a base color, shades are darker.

    0°/0%: 0% Black, 41% Dim Gray, 50% (Web) Gray, 66% Dark Gray, 75% (X11) Gray, 75% Silver, 83% Light Gray, 86% Gainsboro, 96% White Smoke, 100% White
  • 0°/100%: 25% (Web) Maroon, 27% Dark Red, 50% Red, 99% Snow
  • 16°/100%: 50% Orange Red, 66% Coral
  • 33°/100%: 50% Dark Orange, 88% Bisque
  • 36°/100%: 84% Navajo White, 90% Blanched Almond
  • 60°/100%: 25% Olive, 50% Yellow, 94% Light Yellow, 97% Ivory
  • 80°/61%: 35% Olive Drab, 50% Yellow Green
  • 90°/100%: 49% Lawn Green, 50% Chartreuse
  • 120°/61%: 34% Forest Green, 50% Lime Green
  • 120°/100%: 20% Dark Green, 25% (Web) Green, 50% (X11) Green / Lime, 97% Honeydew
  • 146–147°/50%: 36% Sea Green, 47% Medium Sea Green
  • 150°/100%: 50% Spring Green, 98% Mint Cream
  • 180–181°/100%: 25% Teal, 27% Dark Cyan, 41% Dark Turquoise, 50% Aqua / Cyan, 94% Light Cyan, 97% Azure
  • 240°/100%: 25% Navy Blue, 27% Dark Blue, 40% Medium Blue, 50% Blue, 99% Ghost White
  • 300°/100%: 25% (Web) Purple, 27% Dark Magenta, 50% Fuchsia / Magenta
  • 328–330°/100%: 54% Deep Pink, 71% Hot Pink
  • 350–351°/100%: 88% Pink, 86% Light Pink
  • Tones with different saturation

    Some pairs of colors share the same lightness and hue. These tones differ only by saturation. Tones are far less common in the X11 set than nuances, tints and shades.

    0°/41%: 0% Dim Gray, 59% Brown
  • 120°/50%: 61% Lime Green, 100% Green / Lime
  • 180°/25%: 25% Dark Slate Gray, 100% Teal
  • 240°/27%: 64% Midnight Blue, 100% Dark Blue
  • Derived lists

    The Printer Working Group (PWG) of the IEEE publishes a standard, PWG 5101.1, whose mandatory color names are based upon RFC 3805, successor to RFC 1759 which imported the functional color names other, unknown and transparent alongside seven basic colors from ISO 10175 (DPA) and ISO 10180 (SPDL), and JTAPI. This standard has four variants for each non-monochromatic color: clear (50% transparent), dark, light and the default. Wherever possible, the values are the same as in the W3C adaptation of the X11 list, except for Turquoise which is instead of . Missing variant values have been added systematically. Buff and Mustard are completely new color names. Light Black and Gray correspond to the same color.

    |}

    See also

    External links

    Notes and References

    1. News: "Tomato" versus "#FF6347"—the tragicomic history of CSS color names . Ars Technica . October 11, 2015 . October 11, 2015 . Julianne . Tveten.
    2. Book: Nye, Adrian. Xlib programming manual : for version 11 of the X Window System. 1990. O'Reilly & Associates. [Sebastapol, CA]. 0-937175-11-0. 2nd ed. covers release 3 and release 4, major revisions.. registration.
    3. Web site: ModuleVersions. 2014-08-21.
    4. Web site: Remove all traces of external RGB database (and Speedo). 5 November 2007. Stone. Daniel. 2014-08-26.
    5. Web site: ~alanc/xc-historical - Partial/incomplete import of X consortium historical RCS up to X11R6.0. freedesktop.org.
    6. Web site: Last call comments on CSS3 module: color. Alex. Sexton. 12 March 2014. 12 March 2014. www-style@w3.org mailing list. World Wide Web Consortium.
    7. Web site: Netscape.com . Wp.netscape.com . 2013-08-14.
    8. Web site: Cascading Style Sheets, level 1. www.w3.org. 2016-11-15.
    9. Web site: CSS Color Module Level 4. drafts.csswg.org. 2016-11-15.
    10. Web site: Pfister . Daphne . Add aliases for colors that differ between X11 and CSS · freedesktop/xorg-rgb@ca05c39 . GitHub . en.
    11. https://www.w3.org/TR/REC-html40/types.html#h-6.5 HTML 4.0: Basic HTML data types
    12. https://gitlab.freedesktop.org/xorg/app/rgb/raw/master/rgb.txt Current official rgb.txt
    13. Web site: Lists.w3.org . w3.org . April 2002 . 2013-08-14.
    14. Web site: rgb.txt . X.Org Foundation . X colorname to RGB mapping database . 18 September 2017.
    15. Web site: others/old-rgb.txt . X.Org Foundation . X colorname to RGB mapping database . 18 September 2017.
    16. Web site: others/raveling.txt . X.Org Foundation . X colorname to RGB mapping database . 18 September 2017.
    17. Web site: others/README . X.Org Foundation . X colorname to RGB mapping database . 18 September 2017.