forced-color-adjust: auto;
forced-color-adjust: none;

/* Global values */
forced-color-adjust: inherit;
forced-color-adjust: initial;
forced-color-adjust: revert;
forced-color-adjust: revert-layer;
forced-color-adjust: unset;

The forced-color-adjust property's value must be one of the following keywords.

auto

The element's colors are adjusted by the user agent in forced colors mode. This is the default.

none

The element's colors are not automatically adjusted by the user agent in forced colors mode.

This property should only be used to makes changes that will support a user's color and contrast requirements. For example, if you become aware that the color optimizations made by the user agent result in a poor experience when in a high contrast or dark mode. Using this property would enable tweaking of the result in that mode to provide a better experience. It should not be used to prevent user choices being respected.

forced-color-adjust = 
  auto                   |
  none                   |
  preserve-parent-color  

In the example below the first box will use the color scheme that the user has set. For example in Windows High Contrast mode black scheme it will have a black background and white text. The second box will preserve the site colors set on the .box class.

By using the forced-colors media feature you could add any other optimizations for forced color mode alongside the forced-color-adjust property.

CSS

.box {
  border: 5px solid grey;
  background-color: #ccc;
  width: 300px;
  margin: 20px;
  padding: 10px;
}

@media (forced-colors: active) {
  .forced {
    forced-color-adjust: none;
  }
}

HTML

<div class="box">
  <p>This is a box which should use your color preferences.</p>
</div>

<div class="box forced">
  <p>This is a box which should stay the colors set by the site.</p>
</div>

Result

The following screenshot shows the image above in Windows High Contrast Mode:

• Applying color to HTML elements using CSS
• Styling for Windows high contrast with standards for forced colors.
• print-color-adjust