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lab()

The lab() functional notation expresses a given color in the CIE L*a*b* color space. Lab represents the entire range of color that humans can see.

Syntax

lab(29.2345% 39.3825 20.0664);
lab(52.2345% 40.1645 59.9971);
lab(52.2345% 40.1645 59.9971 / .5);

Values

Functional notation: lab(L a b [/ A])
- L is a <number> between 0 and 100 or a <percentage> between 0% and 100% that specifies the CIE Lightness where the number 0 corresponds to 0% (black) and the number 100 corresponds to 100% (white).
- a is a <number> between -125 and 125 or a <percentage> between -100% and 100%, specifying the distance along the a axis in the Lab colorspace, that is how green/red the color is.
- b is a <number> between -125 and 125 or a <percentage> between -100% and 100%, specifying the distance along the b axis in the Lab colorspace, that is how blue/yellow the color is.
- A (alpha) can be a <number> between 0 and 1, or a <percentage>, where the number 1 corresponds to 100% (full opacity).

Note: Usually when percentage values have a numeric equivalent in CSS, 100% is equal to the number 1. This case is notable where 100% is equal to the number 100 for the L value and 125 for the a and b values.

Formal syntax

<lab()> = 
  lab( [ <percentage> | <number> | none ] [ <percentage> | <number> | none ] [ <percentage> | <number> | none ] [ / [ <alpha-value> | none ] ]? )  

<alpha-value> = 
  <number>      |
  <percentage>

Examples

Adjusting lightness and color axes with lab()

The following example shows the effect of varying the lightness, a-axis, and b-axis values of the lab() function.

<div data-color="red"></div>
<div data-color="red-a"></div>

<div data-color="green"></div>
<div data-color="green-b"></div>

<div data-color="blue"></div>
<div data-color="blue-light"></div>

[data-color="red"] {
  background-color: lab(100 125 125);
}
[data-color="red-a"] {
  background-color: lab(100 110 125);
}

[data-color="green"] {
  background-color: lab(75% -120 125);
}
[data-color="green-b"] {
  background-color: lab(75% -120 10);
}

[data-color="blue"] {
  background-color: lab(0 -120 -120);
}
[data-color="blue-light"] {
  background-color: lab(70 -120 -120);
}

Adjusting opacity with lab()

The following example shows the effect of varying the A (alpha) value of the lab() functional notation. The red and red-alpha elements overlap the #background-div element to demonstrate the effect of opacity. Giving A a value of 0.4 makes the color 40% opaque.

<div id="background-div">
  <div data-color="red"></div>
  <div data-color="red-alpha"></div>
</div>

[data-color="red"] {
  background-color: lab(100 125 125);
}
[data-color="red-alpha"] {
  background-color: lab(100 125 125 / 0.4);
}

Specifications

Specification
CSS Color Module Level 4 # lab-colors

Browser compatibility

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	WebView Android	Chrome Android	Firefox for Android	Opera Android	Safari on IOS	Samsung Internet
`lab`	111	111	111	No	97	15	111	111	No	No	15	No