title: UISearchBar background color not working with minimal searchBarStyle
body: <p>I have a <code>UISearchBar</code> to which I want to set a white background.</p>
  
  <p>Since I want to set a custom border, I choose the <code>minimal</code> value for <code>searchBarStyle</code>. </p>
  
  <p>I can obtain a white background by setting <code>backgroundColor</code> and <code>borderStyle</code> to the <code>searchTextField</code> (this field is only available in iOS 13, to access it safely in other iOS versions check <a href="https://stackoverflow.com/a/58067550/3178759">here</a>), as follows:</p>
  
  <pre><code>searchBar.searchTextField.borderStyle = .none
  searchBar.searchTextField.backgroundColor = .white
  </code></pre>
  
  <p>However, <strong>this doesn't work in iOS 13</strong>, it seems that the background color is ignored when <code>searchBarStyle</code> value is <code>minimal</code>, but correctly works for <code>default</code> / <code>prominent</code> styles.</p>