title: How to change blue outline color of a button when clicked [Bootstrap 4]
body: <p>If I click the following button a blue outline appears:</p>
  
  <pre><code>&lt;button onclick="window.location.href='/Downloads'" type="button" class="btn btn-lg btn-primary" style="background-color:green;border-color:green"&gt;Download&lt;/button&gt;
  </code></pre>
  
  <p>How can I change this color?</p>