Unchanged barTintColor UINavigationBar on iOS 13.4

I was having the same issue, what fixed it for me was this:

On the storyboard, for your Navigation Controller change the "Bar Tint" to its "Default" value, then on your code you can change it as you normally would.

    // For the navigation bar
    navigationController?.navigationBar.barTintColor = .red

    // For the title
    let attributes = [NSAttributedString.Key.foregroundColor: UIColor.white ]
    navigationController?.navigationBar.titleTextAttributes = attributes

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I have the code in viewDidLoad()

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Oddly enough for me, it also fixed the issue I was having with the "Status Bar".