title: iOS UITableView Index is transparent
body: <p>As shown in the below image, I have set the table's background and some other styles. The index, highlighted in red, is transparent. How do I set it to be white like the rest of the cell?</p>
  
  <p><img src="https://i.stack.imgur.com/6Rz6S.jpg" alt="enter image description here"> </p>