title: Transparent NavigatorIOS doesn't work
body: <p>I would like to display a 100% transparent Navigator bar, but I have something like light pink instead of the background color :</p>
  
  <p><a href="https://i.stack.imgur.com/fYUk5.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/fYUk5.png" alt="enter image description here"></a></p>
  
  <p>Here is my code : </p>
  
  <pre><code>&lt;NavigatorIOS
  ref='nav'
  tintColor="white"
  style={{flex: 1}}
  initialRoute={{
    title: 'Splash',
    navigationBarHidden: true,
    component: SplashScene
  }}/&gt;
  </code></pre>
  
  <p>Thanks a lot for your help,</p>
  
  <p>Margot</p>