<color>

The <color> CSS data type represents a color in the sRGB color space. 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)
• Using the RGB cubic-coordinate system (via the #-hexadecimal or the rgb() and rgba() functional notations)
• Using the HSL cylindrical-coordinate system (via the hsl() and hsla() functional notations)

Syntax

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

Color keywords

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.

transparent keyword

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).

currentcolor keyword

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

HTML

<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>

Result

RGB colors

The RGB color model defines a given color 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.

HSL colors

The HSL color model defines a given color 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).

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.

System Colors

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

ButtonFace

Background of push buttons

ButtonText

Text of push buttons

Canvas

Background of application content or documents

CanvasText

Text in application content or documents

Field

Background of input fields

FieldText

Text in input fields

GrayText

Text that is disabled

Highlight

Background of items that are selected in a control

HighlightText

Text of items that are selected in a control

LinkText

Text of non-active, non-visited links

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.

Mozilla System Color Extensions

Mozilla Color Preference Extensions

-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.

Interpolation

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.

Accessibility considerations

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.

Examples

Color value tester

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

RGB syntax variations

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(1e2, .5e1, .5e0, +.25e2%)

RGB transparency variations

/* Hexadecimal syntax */
#3a30                    /*   0% opaque green */ 
#3A3F                    /* full opaque green */ 
#33aa3300                /*   0% opaque green */ 
#33AA3380                /*  50% opaque green */ 

/* Functional syntax */
rgba(51, 170, 51, .1)    /*  10% opaque green */ 
rgba(51, 170, 51, .4)    /*  40% opaque green */ 
rgba(51, 170, 51, .7)    /*  70% opaque green */ 
rgba(51, 170, 51,  1)    /* full opaque green */ 

/* Whitespace syntax */
rgba(51 170 51 / 0.4)    /*  40% opaque green */ 
rgba(51 170 51 / 40%)    /*  40% opaque green */ 

/* Functional syntax with floats value */
rgba(255, 0, 153.6, 1)
rgba(1e2, .5e1, .5e0, +.25e2%)

HSL syntax variations

/* These examples all specify the same color: a lavender. */
hsl(270,60%,70%)
hsl(270, 60%, 70%)
hsl(270 60% 70%)
hsl(270deg, 60%, 70%)
hsl(4.71239rad, 60%, 70%)
hsl(.75turn, 60%, 70%)

/* These examples all specify the same color: a lavender that is 15% opaque. */
hsl(270, 60%, 50%, .15)
hsl(270, 60%, 50%, 15%)
hsl(270 60% 50% / .15)
hsl(270 60% 50% / 15%)

Fully saturated colors

Lighter and darker greens

Saturated and desaturated greens

HSL transparency variations

hsla(240, 100%, 50%, .05)     /*   5% opaque blue */ 
hsla(240, 100%, 50%, .4)      /*  40% opaque blue */ 
hsla(240, 100%, 50%, .7)      /*  70% opaque blue */ 
hsla(240, 100%, 50%, 1)       /* full opaque blue */ 

/* Whitespace syntax */
hsla(240 100% 50% / .05)      /*   5% opaque blue */ 

/* Percentage value for alpha */
hsla(240 100% 50% / 5%)       /*   5% opaque blue */ 

Specifications

Browser compatibility

See also

• 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