Change the color of iOS Navigation Bar

In fact, i found that the solution was to use in the AppDelegate.siwft :

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
    // Override point for customization after application launch.
    UINavigationBar.appearance().barTintColor = UIColor(red: 0, green: 0/255, blue: 205/255, alpha: 1)
    UINavigationBar.appearance().tintColor = UIColor.whiteColor()
    UINavigationBar.appearance().titleTextAttributes = [NSForegroundColorAttributeName:UIColor.whiteColor()]

    return true
}

and then in each view controller, that we need another background color or something else

1. the segue should be different than "show"

2. use the func viewWillAppear

    override func viewWillAppear(animated: Bool) {
        super.viewWillAppear(animated)
        self.navigationController?.navigationBar.barTintColor = UIColor.whiteColor()
        self.navigationController?.navigationBar.tintColor = UIColor.blueColor()
        self.navigationController!.navigationBar.titleTextAttributes = [NSForegroundColorAttributeName: UIColor.blueColor()]
   }
   

Swift 4.2:

    //To change Navigation Bar Background Color
    UINavigationBar.appearance().barTintColor = UIColor.blue
    //To change Back button title & icon color
    UINavigationBar.appearance().tintColor = UIColor.white
    //To change Navigation Bar Title Color
    UINavigationBar.appearance().titleTextAttributes = [NSAttributedString.Key.foregroundColor: UIColor.white]

Swift 3.x:

//To change Navigation Bar Background Color
UINavigationBar.appearance().barTintColor = UIColor.blue
//To change Back button title & icon color
UINavigationBar.appearance().tintColor = UIColor.white
//To change Navigation Bar Title Color
UINavigationBar.appearance().titleTextAttributes = [NSForegroundColorAttributeName: UIColor.white]

Updated for Swift 3

    UINavigationBar.appearance().barTintColor = .black
    UINavigationBar.appearance().tintColor = .white
    UINavigationBar.appearance().titleTextAttributes = [NSForegroundColorAttributeName: UIColor.white]
    UINavigationBar.appearance().isTranslucent = false

Swift 4

    UINavigationBar.appearance().barTintColor = .black
    UINavigationBar.appearance().tintColor = .white
    UINavigationBar.appearance().titleTextAttributes = [NSAttributedStringKey.foregroundColor: UIColor.white]
    UINavigationBar.appearance().isTranslucent = false

Swift 5

    UINavigationBar.appearance().barTintColor = .black
    UINavigationBar.appearance().tintColor = .white
    UINavigationBar.appearance().titleTextAttributes = [NSAttributedString.Key.foregroundColor: UIColor.white]
    UINavigationBar.appearance().isTranslucent = false