css/css-pseudo/active-selection-002-manual.html

<!DOCTYPE html>

  <meta charset="UTF-8">

  <title>CSS Pseudo-Elements Test: active selection and background-color (basic)</title>

  <link rel="author" title="Gérard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/">
  <link rel="help" href="https://www.w3.org/TR/css-pseudo-4/#highlight-selectors">
  <link rel="help" href="https://www.w3.org/TR/css-pseudo-4/#highlight-styling">

  <meta content="interact" name="flags">

  <style>
  div
    {
      background-color: red;
      color: aqua;
      display: inline;
      font-size: 300%;
    }

  div::selection
    {
      background-color: green;
    }

  /*
  Chromium 77.0.3855.0 creates a background-color #334C00 or rgb(51, 76, 0)
  and not a green (#008000 or rgb(0, 128, 0)) background color.

  Issue 1018450: background-color of ::selection should be painted as specified
  https://bugs.chromium.org/p/chromium/issues/detail?id=1018450
  */
  </style>

  <p>Instructions: Select a few or all characters from the words "Text sample" using a variety of methods:

  <ul>
    <li>Select by dragging (leftwardedly or rightwardedly) the mouse across the characters.
    <li>Select by using shift + keyboard arrows when keyboard navigation / caret browsing is enabled.
    <li>Double click a word to select it.
    <li>Triple click the text to select it.
  </ul>

  <p>Test passes if, in every case, the background color of selected characters become green <em>and</em> if text color of selected characters remains aqua.

  <div>Text sample</div>