title: Tried to add custom UIBarButtonItem to UIToolBar, but item comes out messed up
body: <p>I'm trying to add a custom button (shape and color) to my UIToolBar, but it comes out much differently than it should.</p>
  
  <p>What button looks like:</p>
  
  <p><img src="https://i.stack.imgur.com/eyyOE.png" alt="enter image description here"></p>
  
  <p>What it looks like in the bar:</p>
  
  <p><img src="https://i.stack.imgur.com/aSOoM.png" alt="enter image description here"></p>
  
  <p>Here's the code I used to add it:</p>
  
  <pre><code>    UIImage *backButtonImage = [UIImage imageNamed:@"back-button.png"];
      UIBarButtonItem *backButton = [[UIBarButtonItem alloc] initWithImage:backButtonImage style:UIBarButtonItemStylePlain target:self action:@selector(backButtonTapped)];
      [toolBarItems addObject:backButton];
  </code></pre>
  
  <p>What exactly am I doing wrong here?</p>