如果你在Settings视图控制器中已经有了后退按钮，你想改变Payment Information视图控制器上后退按钮的颜色为其他颜色，你可以在Settings视图控制器的prepareforsegue中这样做:

override func prepare(for segue: UIStoryboardSegue, sender: Any?) { 
    if segue.identifier == "YourPaymentInformationSegue"
    {
        //Make the back button for "Payment Information" gray:
        self.navigationItem.backBarButtonItem?.tintColor = UIColor.gray               
    }
}

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()

在AppDelegate.swift中的didFinishLaunchingWithOptions函数中添加以下代码

var navigationBarAppearace = UINavigationBar.appearance()

navigationBarAppearace.tintColor = uicolorFromHex(0xffffff) // White color
navigationBarAppearace.barTintColor = uicolorFromHex(0x034517) // Green shade

// change navigation item title color
navigationBarAppearace.titleTextAttributes =[NSForegroundColorAttributeName:UIColor.whiteColor()]

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

斯威夫特5.3:

UINavigationBar.appearance().backIndicatorImage = UIImage(named: "custom-back-image")
UINavigationBar.appearance().backIndicatorTransitionMaskImage = UIImage(named: "custom-back-image")

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)