title: Bootstrap 4 change tooltip arrow color
body: <p>I want to change the tooltip arrow color to red. I've googled about for an hour and the snippets that I found did not work. </p>
  
  <p>My last attempt was:</p>
  
  <pre><code>.tooltip-arrow {
    border-right-color: red;
    border-left-color: red;
    border-bottom-color: red;
    border-top-color: red;
  }
  </code></pre>
  
  <p>The tooltip is positioned right, poiting left.</p>