Summary

The <color> CSS data type denotes a color in the sRGB color space. A color can be described in any of these ways:

Note that the list of accepted color values have been extended as the specification has evolved, culminating with the latest CSS3 colors.

Associated with the color in the sRGB space, a <color> value also consists of an alpha-channel coordinate, transparency value, indicating how the color should composite with its background color.

Though CSS color values are precisely defined, they may appear differently on different output devices. Most of them are not calibrated, and some browsers do not support output devices' color profile. Without these, color rendering may vary a lot.

Note:  The WCAG 2.0 recommendation from the W3C strongly advises web authors not to use color as the only mean to convey a specific information, action or result. Some users have problems distinguishing colors and the conveyed information may not be grasped. Of course, this doesn't prevent the usage of color, only its usage as the only mean to describe some information.

Interpolation

Values of the <color> CSS data type can be interpolated in order to perform animations or for creating <gradient> values. In that case they are interpolated on each of their red, green, blue components, each handled as a real, floating-point number. Note that interpolation of colors happens in the alpha-premultiplied sRGBA color space to prevent unexpected grey colors to appear. In animations, the speed of the interpolation is determined by the timing function associated with the animation.

Values

There are several ways to describe a <color> value.

Color keywords

Color keywords are case-insensitive identifiers which represent a specific color, e.g. red, blue, brown, lightseagreen. The name describes the color, though it is mostly artificial. The list of accepted values varied a lot through the different specification:

  • CSS Level 1 only accepted 16 basic colors, named the VGA colors as they were taken from the set of displayable colors on VGA graphic cards.
  • CSS Level 2 added the orange keyword.
  • From the beginning, browsers accepted other colors, mostly the X11 named colors list as some early browsers were X11 applications, though with a few differences. SVG 1.0 was the first standard to formally define these keywords; CSS Colors Level 3 also formally defined these keywords. They are often referred as the extended color keywords, the X11 colors, or the SVG colors.

There are a few caveats to consider when using keywords:

  • Except the 16 basic colors which are common with HTML, the others cannot be used in HTML. HTML will convert these unknown values with a specific algorithm which will lead to completely different colors. These keywords should only be used in SVG & CSS.
  • Unknown keywords make the CSS property invalid. Invalid properties being ignored, the color will have no effect. This is a different behavior than the one of HTML.
  • No keyword-defined colors in CSS have any transparency, they are plain, solid colors.
  • Several keywords denote the same colors:
    • darkgray / darkgrey
    • darkslategray / darkslategrey
    • dimgray / dimgrey
    • lightgray / lightgrey
    • lightslategray / lightslategrey
    • gray / grey
    • slategray / slategrey
  • Though the names of the keywords have been taken by the usual X11 color names, the color may diverge from the corresponding system color on X11 system as these are tailored for the specific hardware by the manufacturer .
Specification Color Keyword RGB hex values Live
CSS Level 1   black #000000  
  silver #c0c0c0  
  gray[*] #808080  
  white #ffffff  
  maroon #800000  
  red #ff0000  
  purple #800080  
  fuchsia #ff00ff  
  green #008000  
  lime #00ff00  
  olive #808000  
  yellow #ffff00  
  navy #000080  
  blue #0000ff  
  teal #008080  
  aqua #00ffff  
CSS Level 2 (Revision 1)   orange #ffa500  
CSS Color Module Level 3   aliceblue #f0f8ff  
  antiquewhite #faebd7  
  aquamarine #7fffd4  
  azure #f0ffff  
  beige #f5f5dc  
  bisque #ffe4c4  
  blanchedalmond #ffe4c4  
  blueviolet #8a2be2  
  brown #a52a2a  
  burlywood #deb887  
  cadetblue #5f9ea0  
  chartreuse #7fff00  
  chocolate #d2691e  
  coral #ff7f50  
  cornflowerblue #6495ed  
  cornsilk #fff8dc  
  crimson #dc143c  
  darkblue #00008b  
  darkcyan #008b8b  
  darkgoldenrod #b8860b  
  darkgray[*] #a9a9a9  
  darkgreen #006400  
  darkgrey[*] #a9a9a9  
  darkkhaki #bdb76b  
  darkmagenta #8b008b  
  darkolivegreen #556b2f  
  darkorange #ff8c00  
  darkorchid #9932cc  
  darkred #8b0000  
  darksalmon #e9967a  
  darkseagreen #8fbc8f  
  darkslateblue #483d8b  
  darkslategray[*] #2f4f4f  
  darkslategrey[*] #2f4f4f  
  darkturquoise #00ced1  
  darkviolet #9400d3  
  deeppink #ff1493  
  deepskyblue #00bfff  
  dimgray[*] #696969  
  dimgrey[*] #696969  
  dodgerblue #1e90ff  
  firebrick #b22222  
  floralwhite #fffaf0  
  forestgreen #228b22  
  gainsboro #dcdcdc  
  ghostwhite #f8f8ff  
  gold #ffd700  
  goldenrod #daa520  
  greenyellow #adff2f  
  grey #808080  
  honeydew #f0fff0  
  hotpink #ff69b4  
  indianred #cd5c5c  
  indigo #4b0082  
  ivory #fffff0  
  khaki #f0e68c  
  lavender #e6e6fa  
  lavenderblush #fff0f5  
  lawngreen #7cfc00  
  lemonchiffon #fffacd  
  lightblue #add8e6  
  lightcoral #f08080  
  lightcyan #e0ffff  
  lightgoldenrodyellow #fafad2  
  lightgray[*] #d3d3d3  
  lightgreen #90ee90  
  lightgrey[*] #d3d3d3  
  lightpink #ffb6c1  
  lightsalmon #ffa07a  
  lightseagreen #20b2aa  
  lightskyblue #87cefa  
  lightslategray[*] #778899  
  lightslategrey[*] #778899  
  lightsteelblue #b0c4de  
  lightyellow #ffffe0  
  limegreen #32cd32  
  linen #faf0e6  
  mediumaquamarine #66cdaa  
  mediumblue #0000cd  
  mediumorchid #ba55d3  
  mediumpurple #9370db  
  mediumseagreen #3cb371  
  mediumslateblue #7b68ee  
  mediumspringgreen #00fa9a  
  mediumturquoise #48d1cc  
  mediumvioletred #c71585  
  midnightblue #191970  
  mintcream #f5fffa  
  mistyrose #ffe4e1  
  moccasin #ffe4b5  
  navajowhite #ffdead  
  oldlace #fdf5e6  
  olivedrab #6b8e23  
  orangered #ff4500  
  orchid #da70d6  
  palegoldenrod #eee8aa  
  palegreen #98fb98  
  paleturquoise #afeeee  
  palevioletred #db7093  
  papayawhip #ffefd5  
  peachpuff #ffdab9  
  peru #cd853f  
  pink #ffc0cb  
  plum #dda0dd  
  powderblue #b0e0e6  
  rosybrown #bc8f8f  
  royalblue #4169e1  
  saddlebrown #8b4513  
  salmon #fa8072  
  sandybrown #f4a460  
  seagreen #2e8b57  
  seashell #fff5ee  
  sienna #a0522d  
  skyblue #87ceeb  
  slateblue #6a5acd  
  slategray[*] #708090  
  slategrey[*] #708090  
  snow #fffafa  
  springgreen #00ff7f  
  steelblue #4682b4  
  tan #d2b48c  
  thistle #d8bfd8  
  tomato #ff6347  
  turquoise #40e0d0  
  violet #ee82ee  
  wheat #f5deb3  
  whitesmoke #f5f5f5  
  yellowgreen #9acd32  
CSS Color Module Level 4   rebeccapurple #663399  

The color rebeccapurple is equivalent to the color #639, and more information about why it was introduced can be found in this Codepen blog post by Trezy "Honoring a Great Man."

transparent keyword

The transparent keyword represents a fully transparent color, i.e. the color seen will be the background color. Technically, it is a black with alpha channel at its minimum value and is a shortcut for rgba(0,0,0,0).

Historical Note
The transparent keyword wasn't a true color in CSS Level 2 (Revision 1). It was a specific keyword that could be used in place of a regular <color> value on two CSS properties: background and border. It was essentially added to allow to override an inherited solid colors.

With the support of opacity through alpha channels, transparent was redefined as a true color in CSS Colors Level 3 allowing its use in any place where a <color> value is required, like the color property.[**]

currentColor keyword

The currentColor keyword represents the calculated value of the element's color property. It allows to make the color properties inherited by properties or child's element properties that do not inherit it by default.

It can also be used on properties that inherit the calculated value of the element's color property and will be equivalent to the inherit keyword on these elements, if any.

Live example

The color of the line (a color-filled div) adapts to the color of its color property, inherited from its parent.

Live example 1
<div style="color:darkred">
 The color of this text is the same as the one of the line:
  <div style="background:currentcolor; height:1px"></div>
 Some more text.
</div> 

Live example 2
<div style="color:blue; border-bottom: 1px dashed currentcolor;">
 The color of this text is the same as the one of the line:
  <div style="background:currentcolor; height:1px"></div>
 Some more text.
</div> 

rgb()

Colors can be defined using the red-green-blue (RGB) model in two ways:

Hexadecimal notation #RRGGBB and #RGB
  • "#", followed by six hexadecimal characters (0-9, A-F).
  • "#", followed by three hexadecimal characters (0-9, A-F).
The three-digit RGB notation (#RGB) and the six-digit form (#RRGGBB) are equal.
For example, #f03 and #ff0033 represent the same color.
Functional Notation rgb(R,G,B)
"rgb", followed by three <integer> or three <percentage> values.
The integer number 255 corresponds to 100%, and to F or FF in the hexadecimal notation.
/* These examples all specify the same RGB color: */
 
 #f03
 #F03
 #ff0033
 #FF0033
 rgb(255,0,51)
 rgb(255, 0, 51)
 rgb(255, 0, 51.2) /* ERROR! Don't use fractions, use integers */ 
 rgb(100%,0%,20%)
 rgb(100%, 0%, 20%)
 rgb(100%, 0, 20%) /* ERROR! Don't mix up integer and percentage notation */

hsl()

Colors also can be defined the Hue-saturation-lightness model (HSL) using the hsl() functional notation.  The advantage of HSL over RGB is that it is far more intuitive: you can guess at the colors you want, and then tweak. It is also easier to create sets of matching colors (by keeping the hue the same and varying the lightness/darkness, and saturation).

Hue is represented as an angle of the color circle (i.e. the rainbow represented in a circle). This angle is given as a unitless <number>. By definition red=0=360, and the other colors are spread around the circle, so green=120, blue=240, etc. As an angle, it implicitly wraps around such that -120=240 and 480=120.

Saturation and lightness are represented as percentages.
100% is full saturation, and0% is a shade of grey.
100% lightness is white, 0% lightness is black, and 50% lightness is "normal".

hsl(0,  100%,50%)    /* red */   
hsl(30, 100%,50%)                 
hsl(60, 100%,50%)                
hsl(90, 100%,50%)                
hsl(120,100%,50%)    /* green */ 
hsl(150,100%,50%)                
hsl(180,100%,50%)                
hsl(210,100%,50%)                
hsl(240,100%,50%)    /* blue */  
hsl(270,100%,50%)                
hsl(300,100%,50%)                
hsl(330,100%,50%)                
hsl(360,100%,50%)    /* red */   

hsl(120,100%,25%)    /* dark green */  
hsl(120,100%,50%)    /* green */       
hsl(120,100%,75%)    /* light green */ 

hsl(120,100%,50%)    /* green */  
hsl(120, 67%,50%)                 
hsl(120, 33%,50%)                 
hsl(120,  0%,50%)                 

hsl(120, 60%,70%)    /* pastel green */ 

rgba()

Colors can be defined in the Red-green-blue-alpha model (RGBa) using the rgba() functional notation. RGBa extends the RGB color model to include the alpha channel, allowing specification of the opacity of a color.
a means opacity: 0=transparent; 1=opaque;

rgba(255,0,0,0.1)    /* 10% opaque red */  
rgba(255,0,0,0.4)    /* 40% opaque red */  
rgba(255,0,0,0.7)    /* 70% opaque red */  
rgba(255,0,0,  1)    /* full opaque red */ 

hsla()

Colors can be defined in the hue-saturation-lightness-alpha model (HSLa) using the hsla() functional notation. HSLa extends the HSL color model to include the alpha channel, allowing specification of the opacity of a color.
a means opacity: 0=transparent; 1=opaque;

hsla(240,100%,50%,0.05)   /* 5% opaque blue */   
hsla(240,100%,50%, 0.4)   /* 40% opaque blue */  
hsla(240,100%,50%, 0.7)   /* 70% opaque blue */  
hsla(240,100%,50%,   1)   /* full opaque blue */ 

System Colors

Not all system colors are supported on all systems. for use on public web pages.

ActiveBorder
Active window border.
ActiveCaption
Active window caption.  Should be used with CaptionText foreground color.
AppWorkspace
Background color of multiple document interface.
Background
Desktop background.
ButtonFace
Face background color for 3-D elements that appear 3-D due to one layer of surrounding border.  Should be used with ButtonText foreground color.
ButtonHighlight
The color of the border facing the light source for 3-D elements that appear 3-D due to one layer of surrounding border.
ButtonShadow
The color of the border away from the light source for 3-D elements that appear 3-D due to one layer of surrounding border.
ButtonText
Text on push buttons.  Should be used with ButtonFace or ThreeDFace background color.
CaptionText
Text in caption, size box, and scrollbar arrow box.  Should be used with ActiveCaption background color.
GrayText
Grayed (disabled) text.
Highlight
Item(s) selected in a control.  Should be used with HighlightText foreground color.
HighlightText
Text of item(s) selected in a control.  Should be used with Highlight background color.
InactiveBorder
Inactive window border.
InactiveCaption
Inactive window caption.  Should be used with InactiveCaptionText foreground color.
InactiveCaptionText
Color of text in an inactive caption.  Should be used with InactiveCaption background color.
InfoBackground
Background color for tooltip controls.  Should be used with InfoText foreground color.
InfoText
Text color for tooltip controls.  Should be used with InfoBackground background color.
Menu
Menu background.  Should be used with MenuText or -moz-MenuBarText foreground color.
MenuText
Text in menus.  Should be used with Menu background color.
Scrollbar
Scroll bar gray area.
ThreeDDarkShadow
The color of the darker (generally outer) of the two borders away from the light source for 3-D elements that appear 3-D due to two
concentric layers of surrounding border.
ThreeDFace
The face background color for 3-D elements that appear 3-D due to two concentric layers of surrounding border.  Should be used with ButtonText foreground color.
ThreeDHighlight
The color of the lighter (generally outer) of the two borders facing the light source for 3-D elements that appear 3-D due to two
concentric layers of surrounding border.
ThreeDLightShadow
The color of the darker (generally inner) of the two borders facing the light source for 3-D elements that appear 3-D due to two
concentric layers of surrounding border.
ThreeDShadow
The color of the lighter (generally inner) of the two borders away from the light source for 3-D elements that appear 3-D due to two
concentric layers of surrounding border.
Window
Window background.  Should be used with WindowText foreground color.
WindowFrame
Window frame.
WindowText
Text in windows.  Should be used with Window background color.

Mozilla System Color Extensions

-moz-ButtonDefault
The border color that goes around buttons that represent the default action for a dialog box.
-moz-ButtonHoverFace
The background color of a button that the mouse pointer is over (which would be ThreeDFace or ButtonFace when the mouse pointer is not over it).  Should be used with the -moz-ButtonHoverText foreground color.
-moz-ButtonHoverText
The text color of a button that the mouse pointer is over (which would be ButtonText when the mouse pointer is not over it).  Should be used with the -moz-ButtonHoverFace background color.
-moz-CellHighlight
Background color for selected item in a tree widget.  Should be used with -moz-CellHighlightText foreground color.  See also -moz-html-CellHighlight.
-moz-CellHighlightText
Text color for a selected item in a tree.  Should be used with -moz-CellHighlight background color.  See also -moz-html-CellHighlightText.
-moz-Combobox
Background color for comboboxes.  Should be used with -moz-ComboboxText foreground color.  In versions prior to 1.9.2, use -moz-Field instead.
-moz-ComboboxText
Background Text color for comboboxes.  Should be used with -moz-ComboboxText foreground color.  In versions prior to 1.9.2, use -moz-FieldText instead.
-moz-Dialog
Background color for dialog boxes.  Should be used with -moz-DialogText foreground color.
-moz-DialogText
Text color for dialog boxes.  Should be used with -moz-Dialog background color.
-moz-dragtargetzone
-moz-EvenTreeRow
Background color for even-numbered rows in a tree.  Should be used with -moz-FieldText foreground color.  In Gecko versions prior to 1.9, use -moz-Field.  See also -moz-OddTreeRow.
-moz-Field
textfield background color.  Should be used with -moz-FieldText foreground color.
-moz-FieldText
textfield foreground color.  Should be used with -moz-Field, -moz-EvenTreeRow, or -moz-OddTreeRow background colors.
-moz-html-CellHighlight
Background color for highlighted item in HTML select.  Should be used with -moz-html-CellHighlightText foreground color.  Prior to Gecko 1.9, use -moz-CellHighlight.
-moz-html-CellHighlightText
Background color for highlighted item in HTML select.  Should be used with -moz-html-CellHighlight background color.  Prior to Gecko 1.9, use -moz-CellHighlightText.
-moz-mac-accentdarkestshadow
-moz-mac-accentdarkshadow
-moz-mac-accentface
-moz-mac-accentlightesthighlight
-moz-mac-accentlightshadow
-moz-mac-accentregularhighlight
-moz-mac-accentregularshadow
-moz-mac-chrome-active
-moz-mac-chrome-inactive
-moz-mac-focusring
-moz-mac-menuselect
-moz-mac-menushadow
-moz-mac-menutextselect
-moz-MenuHover
Background color for hovered menu item.  Often similar to Highlight.  Should be used with -moz-MenuHoverText or -moz-MenuBarHoverText foreground color.
-moz-MenuHoverText
Foreground color for hovered menu item.  Often similar to HighlightText.  Should be used with -moz-MenuHover background color.
-moz-MenuBarText
Foreground color for text in menu bars.  Often similar to MenuText.  Should be used on top of Menu background.
-moz-MenuBarHoverText
Foreground color for hovered text in menu bars.  Often similar to -moz-MenuHoverText.  Should be used on top of -moz-MenuHover background.
-moz-nativehyperlinktext
default platform hyperlink color
-moz-OddTreeRow
Background color for odd-numbered rows in a tree.  Should be used with -moz-FieldText foreground color.  In Gecko versions prior to 1.9, use -moz-Field.  See also -moz-EvenTreeRow.
-moz-win-communicationstext
Should be used for text in objects with appearance:-moz-win-communications-toolbox.
-moz-win-mediatext
Should be used for text in objects with appearance:-moz-win-media-toolbox.

Mozilla Color Preference Extensions

-moz-activehyperlinktext
User's preference for text color of active links.  Should be used against default document background.
 
-moz-default-background-color
User's preference for document background-color.
 
-moz-default-color
User's preference for text color.
-moz-hyperlinktext
User's preference for text color of unvisited links.  Should be used against default document background.
-moz-visitedhyperlinktext
User's preference for text color of visited links.  Should be used against default document background.

Specifications

Specification Status Comment
CSS Color Module Level 4
The definition of '<color>' in that specification.
Editor's Draft Added rebeccapurple.
CSS Color Module Level 3
The definition of '<color>' in that specification.
Recommendation Deprecated system-colors; added SVG colors; added rgba(), hsl(), hsla() functional notation.
CSS Level 2 (Revision 1)
The definition of '<color>' in that specification.
Recommendation Added the orange color and the system-colors.
CSS Level 1
The definition of '<color>' in that specification.
Recommendation Initial definition

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
keywords colors 1.0 1.0 (1.0) 3.0 [1] 3.5 1.0 (85)
#RRGGBB | #RGB 1.0 1.0 (1.0) 3.0 3.5 1.0 (85)
rgb() 1.0 1.0 (1.0) 4.0 3.5 1.0 (85)
hsl() 1.0 1.0 (1.5) 9.0 9.5 3.1 (525)
rgba() 1.0 3.0 (1.9) 9.0 10.0 3.1 (525)
hsla() 1.0 3.0 (1.9) 9.0 10.0 3.1 (525)
currentColor 1.0 1.5 (1.8) 9.0 9.5 4.0 (528)
transparent 1.0 3.0 (1.9) 9.0 [2] 10.0 3.1 (525)
rebeccapurple 38.0 33 (33) 11 25.0 7.1
Feature Android Firefox Mobile (Gecko) IE Phone Opera Mobile Safari Mobile
Basic support ? ? ? ? ?
rgba() ? ? ? ? (Yes)
rebeccapurple (Yes) 33.0 (33) ? ? 8

[1] The 'e'-grey colors (with an e) (grey, darkgrey, darkslategrey, dimgrey, lightgrey, lightslategrey) are only supported since IE 8.0. IE 3 to IE 6 only support the 'a' variants: gray, darkgray, darkslategray, dimgray, lightgray, lightslategray.

[2] IE 7-8 supports transparent only for background and border. color:transparent is drawn black in IE. IE6 renders transparent borders as black, as well.

See also