Why is the UINavigationBar turning black?

You can animate the translucency of the navigation bar. So in the `viewDidLoad` for your second `UITableViewController`, you can write the following:

override func viewDidLoad() {
self.navigationController?.navigationBar.setBackgroundImage(UIImage(), forBarMetrics: UIBarMetrics.Default)
self.navigationController?.navigationBar.shadowImage = UIImage()
self.navigationController?.navigationBar.tintColor = .blackColor()

// Play around with the duration until you find
// a time interval, you find suitable
UIView.animateWithDuration(2) {
self.navigationController?.navigationBar.translucent = true
}
}