它将通过-(void)viewDidLoad中的这一行来解决:

self.navigationItem.backBarButtonItem.tintColor = UIColor.whiteColor;

你可以通过点击storyboard上的空白区域并在右边的工具栏中选择“Show the file inspector”来改变全局色调，你会在工具栏的底部看到“global tint”选项。

让我们试试这段代码:

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

    let navigationBarAppearace = UINavigationBar.appearance()
    navigationBarAppearace.tintColor = UIColor.whiteColor()  // Back buttons and such
    navigationBarAppearace.barTintColor = UIColor.purpleColor()  // Bar's background color
    navigationBarAppearace.titleTextAttributes = [NSForegroundColorAttributeName:UIColor.whiteColor()]  // Title's text color

    self.window?.backgroundColor = UIColor.whiteColor()
    return true
}

你应该加上这一行

 self.navigationController?.navigationBar.topItem?.backBarButtonItem?.tintColor = .black

在AppDelegate类中使用此代码，在didFinishLaunchingWithOptions中。

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {

UINavigationBar.appearance().tintColor = .white

}

    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