dom-snapshot-includeBlendedBackgroundColors.html

<!DOCTYPE html>
<!-- domSnapshot test for a document to include elements where blended bg color is different from the computed CSS color.  -->
<style>
  .test-item {
    display: inline-block;
    background-color: rgba(0 0 0 / 0.15);
    color: rgb(0 0 0);
    padding: 20px;
  }
</style>
<span class="test-item">This is some test text</span>

chromium/third_party/blink/web_tests/inspector-protocol/resources/dom-snapshot-includeBlendedBackgroundColors.html