css/css-pseudo/highlight-cascade/highlight-paired-cascade-002.html

<!doctype html>
<meta charset="utf-8">
<title>CSS Pseudo-Elements Test: paired cascade: UA default highlight colors are not used when highlight pseudo cascade yields background color</title>
<link rel="author" name="Delan Azabani" href="mailto:dazabani@igalia.com">
<link rel="help" href="https://drafts.csswg.org/css-pseudo-4/#highlight-cascade">
<link rel="match" href="highlight-paired-cascade-002-ref.html">
<meta name="assert" value="This test verifies that setting background-color on ::selection suppresses any UA non-initial used value for color. These properties are highlight colors, which are subject to paired cascade.">
<script src="support/selections.js"></script>
<link rel="stylesheet" href="../support/highlights.css">
<style>
    main {
        font-size: 7em;
        margin: 0.5em;
    }
    main::selection {
        /*
            Used value for color should be initial (black).
            https://web-platform-tests.org/writing-tests/assumptions.html
        */
        background-color: black;
    }
</style>
<p>Test passes if no text is legible below.
<main class="highlight_reftest">FAIL</main>
<script>selectNodeContents(document.querySelector("main"));</script>