在Swift3中，将后退按钮设置为红色。

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

它将通过-(void)viewDidLoad中的这一行来解决:

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

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

self.navigationController?.navigationBar.tintColor = UIColor.redColor()

这段代码具有魔力。而不是红色，改变它作为你的愿望。

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
}

Swift 5更新

如果你需要全局设置后退按钮颜色，你可以简单地使用:

UIBarButtonItem.appearance().tintColor = Asset.pureWhite.color

然后你不需要在每个视图控制器上设置后退按钮的背景色。如果你使用这个，你不能在其他视图控制器上设置返回按钮的颜色

BUT

如果您需要在视图控制器上设置后退按钮颜色或在另一个视图控制器上更改，请不要使用上述方法。你可以用:

let appearance = UINavigationBarAppearance()
appearance.titleTextAttributes = [.font:FontFamily.BatonTurbo.medium.font(size: 20),
                                  .foregroundColor: Asset.pureWhite.color] // Naviagtion Title attributes
appearance.backgroundColor = .red // Navigation bar background color

self.navigationItem.standardAppearance = appearance
self.navigationItem.scrollEdgeAppearance = appearance
self.navigationItem.compactAppearance = appearance

navigationController?.navigationBar.tintColor = .green // Back button color