color-mix()

Functional notation: color-mix(<color-interpolation-method>, <color>[<percentage>], <color>[<percentage>])

<color-interpolation-method>

Specifies what interpolation method should be used to mix the colors. It consists of the in keyword followed by a color space name. The following three types are available:

• <rectangular-color-space>: srgb, srgb-linear, display-p3, a98-rgb, prophoto-rgb, rec2020, lab, oklab, xyz, xyz-d50, and xyz-d65.
• <polar-color-space>: hsl, hwb, lch, and oklch.
• custom-color-space: <dashed-ident> referring to a custom @color profile

Note: When browsers support @color-profile, custom color spaces may be supported. Currently, the color space must be one of the available color spaces listed in the formal_syntax.

<color>

A <color> value to mix.

<percentage> Optional

A <percentage> value between 0% and 100%, specifying the amount of the corresponding color to mix.

The two color percentages (we'll refer to them as p1 and p2) are normalized as follows:

• If both p1 and p2 are omitted, then p1 = p2 = 50%.
• If p1 is omitted, then p1 = 100% - p2.
• If p2 is omitted, then p2 = 100% - p1.
• If p1 = p2 = 0%, the function is invalid.
• If p1 + p2 ≠ 100%, then p1' = p1 / (p1 + p2) and p2' = p2 / (p1 + p2), where p1' and p2' are the normalization results.
  • If p1 + p2 < 100%, then an alpha multiplier of p1 + p2 is applied to the resulting color. This is similar to mixing in transparent, with percentage pt = 100% - p1 - p2.

<color-mix()> = 
  color-mix( <color-interpolation-method> , [ <color> && <percentage [0,100]>? ]#{2} )  

<color-interpolation-method> = 
  in [ <rectangular-color-space> | <polar-color-space> <hue-interpolation-method>? ]  

<rectangular-color-space> = 
  srgb          |
  srgb-linear   |
  display-p3    |
  a98-rgb       |
  prophoto-rgb  |
  rec2020       |
  lab           |
  oklab         |
  xyz           |
  xyz-d50       |
  xyz-d65       

<polar-color-space> = 
  hsl    |
  hwb    |
  lch    |
  oklch  

<hue-interpolation-method> = 
  [ shorter | longer | increasing | decreasing ] hue  

The following live demo mixes two colors, color-one and color-two, using the color-mix() function. The source colors are shown on the outside, and the mixed color is shown in the middle. You can change colors by clicking on them and choosing a new color using the resulting color picker. You can also change the percentage of each color included in the mix using the sliders, and the color space using the drop-down menu.

This example demonstrates mixing two colors, blue #a71e14 at different percentages and white with no percentage given. The higher the percentage of #a71e14 is mixed, the more blue and less white the output color is.

HTML

<ul>
  <li>0%</li>
  <li>25%</li>
  <li>50%</li>
  <li>75%</li>
  <li>100%</li>
  <li></li>
</ul>

CSS

The color-mix() function is used to add increasing percentages of blue, up to 100%. The 6th <li> doesn't include a percentage for either color.

ul {
  display: flex;
  list-style-type: none;
  font-size: 150%;
  gap: 10px;
  border: 2px solid;
  padding: 10px;
}

li {
  padding: 10px;
  flex: 1;
  box-sizing: border-box;
  font-family: monospace;
  outline: 3px solid #a71e14;
  text-align: center;
}

li:nth-child(1) {
  background-color: color-mix(in oklab, #a71e14 0%, white);
}

li:nth-child(2) {
  background-color: color-mix(in oklab, #a71e14 25%, white);
}

li:nth-child(3) {
  background-color: color-mix(in oklab, #a71e14 50%, white);
}

li:nth-child(4) {
  background-color: color-mix(in oklab, #a71e14 75%, white);
}

li:nth-child(5) {
  background-color: color-mix(in oklab, #a71e14 100%, white);
}

li:nth-child(6) {
  background-color: color-mix(in oklab, #a71e14, white);
}

Result

The total value of both colors in a color-mix() function is 100%, even if the values set by the developer don't total 100%. In this example, as only one color has a percentage assigned, the other color is implicitly given a percentage value so that the combined total equals 100%. In the last <li>, where neither color is assigned a percentage, both default to 50%.

This example demonstrates using the color-mix() function to add transparency to a color by mixing any color with transparent.

HTML

<ul>
  <li>0%</li>
  <li>25%</li>
  <li>50%</li>
  <li>75%</li>
  <li>100%</li>
  <li></li>
</ul>

CSS

The color-mix() function is used to add increasing percentages of red, which is declared using a custom property named --base, defined on the :root. The 6th <li> doesn't include a percentage, creating an output color that is half as opaque as the --base color. We include a striped background on the <ul> to make the transparency visible.

ul {
  display: flex;
  list-style-type: none;
  font-size: 150%;
  gap: 10px;
  border: 2px solid;
  padding: 10px;
}

li {
  padding: 10px;
  flex: 1;
  box-sizing: border-box;
  font-family: monospace;
  outline: 1px solid var(--base);
  text-align: center;
}

:root {
  --base: red;
}

ul {
  background: repeating-linear-gradient(
    45deg,
    chocolate 0px 2px,
    white 2px 12px
  );
}

li:nth-child(1) {
  background-color: color-mix(in srgb, var(--base) 0%, transparent);
}

li:nth-child(2) {
  background-color: color-mix(in srgb, var(--base) 25%, transparent);
}

li:nth-child(3) {
  background-color: color-mix(in srgb, var(--base) 50%, transparent);
}

li:nth-child(4) {
  background-color: color-mix(in srgb, var(--base) 75%, transparent);
}

li:nth-child(5) {
  background-color: color-mix(in srgb, var(--base) 100%, transparent);
}

li:nth-child(6) {
  background-color: color-mix(in srgb, var(--base), transparent);
}

Result

In this way, the color-mix() function can be used to add transparency to any color, even if the color is already non-opaque (with an alpha channel value < 1). However, color-mix() can't be used to make a semi-transparent color fully opaque. For this, use a relative color with a CSS color function. Relative colors can alter the value of any color channel, including increasing a color's alpha channel to render the color fully opaque.

This example demonstrates the hue interpolation methods available to the color-mix() function. When using hue interpolation, the resulting hue is between the hue values of the two colors being mixed. The value will be different based on which route is taken around the color wheel.

For more information, see <hue-interpolation-method>.

<p>longer</p>
<ul>
  <li>100%</li>
  <li>80%</li>
  <li>60%</li>
  <li>40%</li>
  <li>20%</li>
  <li>0%</li>
</ul>
<p>shorter</p>
<ul>
  <li>100%</li>
  <li>80%</li>
  <li>60%</li>
  <li>40%</li>
  <li>20%</li>
  <li>0%</li>
</ul>
<p>increasing</p>
<ul>
  <li>100%</li>
  <li>80%</li>
  <li>60%</li>
  <li>40%</li>
  <li>20%</li>
  <li>0%</li>
</ul>
<p>decreasing</p>
<ul>
  <li>100%</li>
  <li>80%</li>
  <li>60%</li>
  <li>40%</li>
  <li>20%</li>
  <li>0%</li>
</ul>

CSS

The shorter hue interpolation method takes the shorter route around the color wheel, whereas the longer hue interpolation method takes the longer route. With increasing hue, the route starts with increasing values. With decreasing hue the value decreases. We mix two <named-color> values to create a series of lch() intermediary colors that differ based on which route is taken around the color wheel. The mixed colors include red, blue, and yellow with LCH hue values of approximately 41deg, 301deg, and 100deg, respectively.

To reduce code redundancy, we used CSS custom properties for both colors and for the interpolation method, setting different values on each <ul>.

body {
  font-family: monospace;
}
ul {
  display: flex;
  list-style-type: none;
  font-size: 150%;
  gap: 10px;
  padding: 10px;
  margin: 0;
}

li {
  padding: 10px;
  flex: 1;
  outline: 1px solid var(--base);
  text-align: center;
}

ul:nth-of-type(1) {
  --distance: longer; /* 52 degree hue increments */
  --base: red;
  --mixin: blue;
}
ul:nth-of-type(2) {
  /* 20 degree hue decrements */
  --distance: shorter;
  --base: red;
  --mixin: blue;
}
ul:nth-of-type(3) {
  /* 40 degree hue increments */
  --distance: increasing;
  --base: yellow;
  --mixin: blue;
}
ul:nth-of-type(4) {
  /* 32 degree hue decrements */
  --distance: decreasing;
  --base: yellow;
  --mixin: blue;
}

li:nth-child(1) {
  background-color: color-mix(
    in lch var(--distance) hue,
    var(--base) 100%,
    var(--mixin)
  );
}

li:nth-child(2) {
  background-color: color-mix(
    in lch var(--distance) hue,
    var(--base) 80%,
    var(--mixin)
  );
}

li:nth-child(3) {
  background-color: color-mix(
    in lch var(--distance) hue,
    var(--base) 60%,
    var(--mixin)
  );
}

li:nth-child(4) {
  background-color: color-mix(
    in lch var(--distance) hue,
    var(--base) 40%,
    var(--mixin)
  );
}

li:nth-child(5) {
  background-color: color-mix(
    in lch var(--distance) hue,
    var(--base) 20%,
    var(--mixin)
  );
}

li:nth-child(6) {
  background-color: color-mix(
    in lch var(--distance) hue,
    var(--base) 0%,
    var(--mixin)
  );
}

Result

With longer hue the increments or decrements between colors will always be the same or larger than when using shorter hue. Use increasing hue or decreasing hue when the direction of the hue value change is more important than the length between values.

• <color>
• <color-interpolation-method>
• <hue>
• CSS relative colors