在Swift 4中，你可以使用以下方法来解决这个问题:

let navStyles = UINavigationBar.appearance()
// This will set the color of the text for the back buttons.
navStyles.tintColor = .white
// This will set the background color for navBar
navStyles.barTintColor = .black

    self.navigationController?.navigationBar.tintColor = UIColor.black // to change the all text color in navigation bar or navigation 
    self.navigationController?.navigationBar.barTintColor = UIColor.white // change the navigation background color
    self.navigationController?.navigationBar.titleTextAttributes = [NSForegroundColorAttributeName:UIColor.black] // To change only navigation bar title text color

你可以用这个。把它放在AppDelegate.swift中。

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
        // Override point for customization after application launch.

        UINavigationBar.appearance().translucent = false
        UINavigationBar.appearance().barTintColor = UIColor(rgba: "#2c8eb5")
        UINavigationBar.appearance().tintColor = UIColor.whiteColor()
        UINavigationBar.appearance().titleTextAttributes = [NSForegroundColorAttributeName:UIColor.whiteColor()]

        return true
    }

你应该这样使用:

navigationController?.navigationBar.barTintColor = .purple
navigationController?.navigationBar.tintColor = .white

斯威夫特5.5

更改完整的应用程序主题

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
     // Set for app
     UINavigationBar.appearance().tintColor = .white
     return true
}

更改特定控制器

let navController = UINavigationController.init(rootViewController: yourViewController) 
navController.navigationBar.tintColor = .red

present(navController, animated: true, completion: nil)

在swift 2.0使用中

self.navigationController!.navigationBar.tintColor = UIColor.whiteColor();