我更喜欢自定义NavigationController而不是设置全局ui，或者放在ViewController中。

这是我的解决方案

class AppNavigationController : UINavigationController {

  override func viewDidLoad() {
    super.viewDidLoad()
    self.delegate = self
  }

  override func viewWillAppear(_ animated: Bool) {

  }

}
extension AppNavigationController : UINavigationControllerDelegate {

  func navigationController(_ navigationController: UINavigationController, willShow viewController: UIViewController, animated: Bool) {
    let backButtonItem = UIBarButtonItem(
      title: "   ",
      style: UIBarButtonItem.Style.plain,
      target: nil,
      action: nil)
    backButtonItem.tintColor = UIColor.gray
    viewController.navigationItem.backBarButtonItem = backButtonItem
  }

  func navigationController(_ navigationController: UINavigationController, didShow viewController: UIViewController, animated: Bool) {

  }

}

此外，如果你使用全局设置ui，如UIBarButtonItem.appearance()，你不需要像EKEventEditViewController,PickerViewController等苹果Api。tintColor = .white

你应该加上这一行

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

如果你试了很多次都没有成功，你可以试试:

UIBarButtonItem.appearance(whenContainedInInstancesOf: [UINavigationBar.self]).tintColor = .red

其实，我试了很多次，才发现这种方法行得通。

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Swift3中，将后退按钮设置为红色。

self.navigationController?.navigationBar.tintColor = UIColor.red

你只有一个选择把你的后退按钮藏起来，用你自己来做。 然后设置它的颜色。

我这样做了:

self.navigationItem.setHidesBackButton(true, animated: true)
let backbtn = UIBarButtonItem(title: "Back", style:UIBarButtonItemStyle.Plain, target: self, action: "backTapped:")
self.navigationItem.leftBarButtonItem = backbtn
self.navigationItem.leftBarButtonItem?.tintColor = UIColor.grayColor()