<color>

The <color> CSS data type represents a color. A <color> may also include an alpha-channel transparency value, indicating how the color should composite with its background.

A <color> can be defined in any of the following ways:

• Using a keyword (such as blue or transparent). All existing keywords specify a color in the sRGB color space
• Using the RGB cubic-coordinate system (via the #-hexadecimal or the rgb() and rgba() functional notations). These always specify a color in the sRGB color space
• Using the HSL cylindrical-coordinate system (via the hsl() and hsla() functional notations). These always specify a color in the sRGB color space
• Using the HWB cylindrical-coordinate system (via the hwb() functional notation). These always specify a color in the sRGB color space
• Using the LCH cylindrical coordinate system, via the lch() functional notation. This can specify any visible color.
• Using the Lab coordinate system, via the lab() functional notation. This can specify any visible color.
• Using the color() functional notation, to specify a color in a variety of predefined or custom color spaces.

The <color> data type is specified using one of the options listed below.

Color keywords are case-insensitive identifiers that represent a specific color, such as red, blue, black, or lightseagreen. Although the names more or less describes their respective colors, they are essentially artificial, without a strict rationale behind the names used.

There are a few caveats to consider when using color keywords:

• HTML only recognizes the 16 basic color keywords found in CSS1, using a specific algorithm to convert unrecognized values (often to completely different colors). The other color keywords should only be used in CSS and SVG.
• Unlike HTML, CSS will completely ignore unknown keywords.
• The color keywords all represent plain, solid colors, without transparency.
• Several keywords are aliases for each other:
  • aqua / cyan
  • fuchsia / magenta
  • darkgray / darkgrey
  • darkslategray / darkslategrey
  • dimgray / dimgrey
  • lightgray / lightgrey
  • lightslategray / lightslategrey
  • gray / grey
  • slategray / slategrey
• Though many keywords have been adapted from X11, their RGB values may differ from the corresponding color on X11 systems since manufacturers sometimes tailor X11 colors to their specific hardware.

The transparent keyword represents a fully transparent color. This makes the background behind the colored item completely visible. Technically, transparent is a shortcut for rgba(0,0,0,0).

The currentColor keyword represents the value of an element's color property. This lets you use the color value on properties that do not receive it by default.

If currentColor is used as the value of the color property, it instead takes its value from the inherited value of the color property.

currentColor example

<div style="color:blue; border: 1px dashed currentColor;">
  The color of this text is blue.
  <div style="background:currentColor; height:9px;"></div>
  This block is surrounded by a blue border.
</div>

The RGB color model defines a given color in the sRGB color space according to its red, green, and blue components. An optional alpha component represents the color's transparency.

Syntax

RGB colors can be expressed through both hexadecimal (prefixed with #) and functional (rgb(), rgba()) notations.

Hexadecimal notation: #RRGGBB[AA]

R (red), G (green), B (blue), and A (alpha) are hexadecimal characters (0–9, A–F). A is optional. For example, #ff0000 is equivalent to #ff0000ff.

Hexadecimal notation: #RGB[A]

R (red), G (green), B (blue), and A (alpha) are hexadecimal characters (0–9, A–F). A is optional. The three-digit notation (#RGB) is a shorter version of the six-digit form (#RRGGBB). For example, #f09 is the same color as #ff0099. Likewise, the four-digit RGB notation (#RGBA) is a shorter version of the eight-digit form (#RRGGBBAA). For example, #0f38 is the same color as #00ff3388.

Functional notation: rgb[a](R, G, B[, A])

R (red), G (green), and B (blue) can be either <number>s or <percentage>s, where the number 255 corresponds to 100%. A (alpha) can be a <number> between 0 and 1, or a <percentage>, where the number 1 corresponds to 100% (full opacity).

Functional notation: rgb[a](R G B[ / A])

CSS Colors Level 4 adds support for space-separated values in the functional notation.

The HSL color model defines a given color in the sRGB color space according to its hue, saturation, and lightness components. An optional alpha component represents the color's transparency.

Many designers find HSL more intuitive than RGB, since it allows hue, saturation, and lightness to each be adjusted independently. HSL can also make it easier to create a set of matching colors (such as when you want multiple shades of a single hue). However, using HSL to create color variations can produce surprising results, as it is not perceptually uniform. For example, both hsl(240 100% 50%) and hsl(60 100% 50%) have the same lightness, even though the former is much darker than the latter.

Syntax

HSL colors are expressed through the functional hsl() and hsla() notations.

Functional notation: hsl[a](H, S, L[, A])

H (hue) is an <angle> of the color circle given in degs, rads, grads, or turns in CSS Color Module Level 4. When written as a unitless <number>, it is interpreted as degrees, as specified in CSS Color Module Level 3. By definition, red=0deg=360deg, with the other colors spread around the circle, so green=120deg, blue=240deg, etc. As an <angle>, it implicitly wraps around such that -120deg=240deg, 480deg=120deg, -1turn=1turn, etc.

S (saturation) and L (lightness) are percentages. 100% saturation is completely saturated, while 0% is completely unsaturated (gray). 100% lightness is white, 0% lightness is black, and 50% lightness is "normal."

A (alpha) can be a <number> between 0 and 1, or a <percentage>, where the number 1 corresponds to 100% (full opacity).

Functional notation: hsl[a](H S L[ / A])

CSS Colors Level 4 adds support for space-separated values in the functional notation.

Similar to HSL color model, the HWB color model defines a given color in the sRGB color space according to its hue, whiteness and blackness components.

As with HSL, HWB can be more intuitive to use than RGB. A hue is specified in the same way, followed by the amount of whiteness and blackness, respectively, in percentage values. This function also accepts a alpha value.

Syntax

HWB colors are expressed through the functional hwb() notation.

Functional notation: hwb(H W B[ / A])

Same as HSL: H (hue) is an <angle> of the color circle given in degs, rads, grads, or turns in CSS Color Module Level 4. When written as a unitless <number>, it is interpreted as degrees, as specified in CSS Color Module Level 3. By definition, red=0deg=360deg, with the other colors spread around the circle, so green=120deg, blue=240deg, etc. As an <angle>, it implicitly wraps around such that -120deg=240deg, 480deg=120deg, -1turn=1turn, etc.

W (whiteness) and B (blackness) are percentages. These two colors mix, so you would need 0% whiteness and 100% blackness to produce the color black. And vice versa 100% whiteness and 0% blackness for the color white. 50% of both values renders a mid grey and any other variations a shade of the hue specified.

A (alpha), optional, can be a <number> between 0 and 1, or a <percentage>, where the number 1 corresponds to 100% (full opacity). When specifying an alpha value it must be preceded with a forward slash (/).

In forced colors mode (detectable with the forced-colors media query), most colors are restricted into a user- and browser-defined palette. These system colors are exposed by the following keywords, which can be used to ensure that the rest of the page integrates well with the restricted palette. These values may also be used in other contexts, but are not widely supported by browsers.

The keywords in the following list are defined by the CSS Color Module Level 4 specification.

ActiveText

Text of active links

ButtonBorder

Base border color of controls

ButtonFace

Background color of controls

ButtonText

Foreground color of controls

Canvas

Background of application content or documents

CanvasText

Foreground color in application content or documents

Field

Background of input fields

FieldText

Text in input fields

GrayText

Foreground color for disabled items (e.g. a disabled control)

Highlight

Background of selected items

HighlightText

Foreground color of selected items

LinkText

Text of non-active, non-visited links

Mark

Background of text that has been specially marked (such as by the HTML mark element)

MarkText

Text that has been specially marked (such as by the HTML mark element)

VisitedText

Text of visited links

Deprecated system color keywords

The following keywords were defined in earlier versions of the CSS Color Module. They are now deprecated. for use on public web pages.

ActiveBorder

Active window border.

ActiveCaption

Active window caption. Should be used with CaptionText as foreground color.

AppWorkspace

Background color of multiple document interface.

Background

Desktop background.

ButtonHighlight

The color of the border facing the light source for 3-D elements that appear 3-D due to that 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 that layer of surrounding border.

CaptionText

Text in caption, size box, and scrollbar arrow box. Should be used with the ActiveCaption background color.

InactiveBorder

Inactive window border.

InactiveCaption

Inactive window caption. Should be used with the InactiveCaptionText foreground color.

InactiveCaptionText

Color of text in an inactive caption. Should be used with the InactiveCaption background color.

InfoBackground

Background color for tooltip controls. Should be used with the InfoText foreground color.

InfoText

Text color for tooltip controls. Should be used with the InfoBackground background color.

Menu

Menu background. Should be used with the MenuText or -moz-MenuBarText foreground color.

MenuText

Text in menus. Should be used with the Menu background color.

Scrollbar

Background color of scroll bars.

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 the 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 the WindowText foreground color.

WindowFrame

Window frame.

WindowText

Text in windows. Should be used with the Window background color.

-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 the -moz-CellHighlightText foreground color. See also -moz-html-CellHighlight.

-moz-CellHighlightText

Text color for a selected item in a tree. Should be used with the -moz-CellHighlight background color. See also -moz-html-CellHighlightText.

-moz-Combobox

Background color for combo-boxes. Should be used with the -moz-ComboboxText foreground color. In versions prior to 1.9.2, use -moz-Field instead.

-moz-ComboboxText

Text color for combo-boxes. Should be used with the -moz-Combobox background color. In versions prior to 1.9.2, use -moz-FieldText instead.

-moz-Dialog

Background color for dialog boxes. Should be used with the -moz-DialogText foreground color.

-moz-DialogText

Text color for dialog boxes. Should be used with the -moz-Dialog background color.

-moz-dragtargetzone, -moz-EvenTreeRow

Background color for even-numbered rows in a tree. Should be used with the -moz-FieldText foreground color. In Gecko versions prior to 1.9, use -moz-Field. See also -moz-OddTreeRow.

-moz-html-CellHighlight

Background color for highlighted item in HTML <select>s. Should be used with the -moz-html-CellHighlightText foreground color. Prior to Gecko 1.9, use -moz-CellHighlight.

-moz-html-CellHighlightText

Text color for highlighted items in HTML <select>s. Should be used with the -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

Accent colors.

-moz-mac-chrome-active, -moz-mac-chrome-inactive

Colors for inactive and active browser chrome.

-moz-mac-focusring, -moz-mac-menuselect, -moz-mac-menushadow, -moz-mac-menutextselect, -moz-MenuHover

Background color for hovered menu items. Often similar to Highlight. Should be used with the -moz-MenuHoverText or -moz-MenuBarHoverText foreground color.

-moz-MenuHoverText

Text color for hovered menu items. Often similar to HighlightText. Should be used with the -moz-MenuHover background color.

-moz-MenuBarText

Text color in menu bars. Often similar to MenuText. Should be used on top of Menu background.

-moz-MenuBarHoverText

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 the -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.

-moz-win-accentcolor

Used to access the Windows 10 custom accent color that you can set on the start menu, taskbar, title bars, etc.

-moz-win-accentcolortext

Used to access the color of text placed over the Windows 10 custom accent color in the start menu, taskbar, title bars, etc.

-moz-activehyperlinktext

User's preference for text color of active links. Should be used with the default document background color.

-moz-default-background-color

User's preference for the document background color.

-moz-default-color

User's preference for the text color.

-moz-hyperlinktext

User's preference for the text color of unvisited links. Should be used with the default document background color.

-moz-visitedhyperlinktext

User's preference for the text color of visited links. Should be used with the default document background color.

CSS Color 4 introduced Lab colors. Lab colors are specified via the lab() functional notation. They are not limited to a specific color space, and can represent the entire spectrum of human vision.

CSS Color 4 introduced LCH colors. LCH colors are specified via the lch() functional notation. They are not limited to a specific color space, and can represent the entire spectrum of human vision.

In fact, LCH is the polar form of Lab. It is more human friendly than Lab, as its chroma and hue components specify qualities of the desired color, as opposed to mixing. It is similar to HSL in that way, although it is far more perceptually uniform. Unlike HSL that describes both hsl(60 100% 50%) hsl(240 100% 50%) as having the same lightness, LCH (and Lab) correctly ascribes different lightnesses to them: the former (yellow) has an L of 97.6 and the latter (blue) an L of 29.6. Therefore, LCH can be used to create palettes across entirely different colors, with predictable results. Please note that LCH hue is not the same as HSL hue and LCH chroma is not the same as HSL saturation, although they do share some conceptual similarities.

CSS Color 4 introduced this notation. Colors specified via the color() function can specify a color in any of the predefined color spaces, as well as custom color spaces, defined via the @color-profile rule.

In animations and gradients, <color> values are interpolated on each of their red, green, and blue components. Each component is interpolated as a real, floating-point number. Note that interpolation of colors happens in the alpha-premultiplied sRGBA color space to prevent unexpected gray colors from appearing. In animations, the interpolation's speed is determined by the timing function.

Some people have difficulty distinguishing colors. The WCAG 2.0 recommendation strongly advises against using color as the only means of conveying a specific message, action, or result. See Color and color contrast for more information.

In this example we provide a <div> and a text input. Entering a valid color into the input causes the <div> to adopt that color, allowing you to test our color values.

HTML

<div></div>
<hr>
<label for="color">Enter a valid color value:</label>
<input type="text" id="color">

CSS

div {
  width: 100%;
  height: 200px;
}

const inputElem = document.querySelector('input');
const divElem = document.querySelector('div');

function validTextColor(stringToTest) {
  if (stringToTest === "") { return false; }
  if (stringToTest === "inherit") { return false; }
  if (stringToTest === "transparent") { return false; }

  const image = document.createElement("img");
  image.style.color = "rgb(0, 0, 0)";
  image.style.color = stringToTest;
  if (image.style.color !== "rgb(0, 0, 0)") { return true; }
  image.style.color = "rgb(255, 255, 255)";
  image.style.color = stringToTest;
  return image.style.color !== "rgb(255, 255, 255)";
}

inputElem.addEventListener('change', () => {
  if(validTextColor(inputElem.value)) {
    divElem.style.backgroundColor = inputElem.value;
    divElem.textContent = '';
  } else {
    divElem.style.backgroundColor = 'white';
    divElem.textContent = 'Invalid color value';
  }
});

Result

This example shows the many ways in which a single color can be created with the various RGB color syntaxes.

/* These syntax variations all specify the same color: a fully opaque hot pink. */

/* Hexadecimal syntax */
#f09
#F09
#ff0099
#FF0099

/* Functional syntax */
rgb(255,0,153)
rgb(255, 0, 153)
rgb(255, 0, 153.0)
rgb(100%,0%,60%)
rgb(100%, 0%, 60%)
rgb(100%, 0, 60%) /* ERROR! Don't mix numbers and percentages. */
rgb(255 0 153)

/* Hexadecimal syntax with alpha value */
#f09f
#F09F
#ff0099ff
#FF0099FF

/* Functional syntax with alpha value */
rgb(255, 0, 153, 1)
rgb(255, 0, 153, 100%)

/* Whitespace syntax */
rgb(255 0 153 / 1)
rgb(255 0 153 / 100%)

/* Functional syntax with floats value */
rgb(255, 0, 153.6, 1)
rgb(2.55e2, 0e0, 1.53e2, 1e2%)

• The opacity property lets you define transparency at the element level.
• Some common properties that use this data type: color, background-color, border-color, box-shadow, outline-color, text-shadow
• Applying color to HTML elements using CSS