title: How can I change the popover color frame?
body: <p>I would change the popover color in an ipad splitview application.</p>
  
  <p>So I would change the default blue color:</p>
  
  <p><img src="https://i.stack.imgur.com/7ICiG.png" alt="enter image description here"></p>
  
  <p>in a red color for example. How can I do?</p>