这里有一些非常基本的外观定制，你可以应用于整个应用程序:

UINavigationBar.appearance().backgroundColor = UIColor.greenColor()
UIBarButtonItem.appearance().tintColor = UIColor.magentaColor()
//Since iOS 7.0 UITextAttributeTextColor was replaced by NSForegroundColorAttributeName
UINavigationBar.appearance().titleTextAttributes = [UITextAttributeTextColor: UIColor.blueColor()]
UITabBar.appearance().backgroundColor = UIColor.yellowColor();

斯威夫特5.4.2:

UINavigationBar.appearance().backgroundColor = .green // backgorund color with gradient
// or
UINavigationBar.appearance().barTintColor = .green  // solid color
    
UIBarButtonItem.appearance().tintColor = .magenta
UINavigationBar.appearance().titleTextAttributes = [NSAttributedString.Key.foregroundColor : UIColor.blue]
UITabBar.appearance().barTintColor = .yellow

更多关于UIAppearance API在Swift你可以阅读这里。

iOs 14 +

init() {        
    let appearance = UINavigationBarAppearance()
    appearance.shadowColor = .clear // gets also rid of the bottom border of the navigation bar
    appearance.configureWithTransparentBackground() 
    UINavigationBar.appearance().standardAppearance = appearance
    UINavigationBar.appearance().scrollEdgeAppearance = appearance
}

在Swift 2中

在导航栏中更改颜色，

navigationController?.navigationBar.barTintColor = UIColor.whiteColor()

在项目导航栏中更改颜色，

navigationController?.navigationBar.tintColor = UIColor.blueColor()

or

navigationController!.navigationBar.titleTextAttributes = [NSForegroundColorAttributeName: UIColor.blueColor()]

这里有一些非常基本的外观定制，你可以应用于整个应用程序:

UINavigationBar.appearance().backgroundColor = UIColor.greenColor()
UIBarButtonItem.appearance().tintColor = UIColor.magentaColor()
//Since iOS 7.0 UITextAttributeTextColor was replaced by NSForegroundColorAttributeName
UINavigationBar.appearance().titleTextAttributes = [UITextAttributeTextColor: UIColor.blueColor()]
UITabBar.appearance().backgroundColor = UIColor.yellowColor();

斯威夫特5.4.2:

UINavigationBar.appearance().backgroundColor = .green // backgorund color with gradient
// or
UINavigationBar.appearance().barTintColor = .green  // solid color
    
UIBarButtonItem.appearance().tintColor = .magenta
UINavigationBar.appearance().titleTextAttributes = [NSAttributedString.Key.foregroundColor : UIColor.blue]
UITabBar.appearance().barTintColor = .yellow

更多关于UIAppearance API在Swift你可以阅读这里。

没有一个解决方案对我有效，所以我分享一个有效的。

Swift 5, Xcode 13.4.1

将以下内容放入viewDidLoad():

let appearance = UINavigationBarAppearance()
        appearance.configureWithOpaqueBackground()
        appearance.backgroundColor = UIColor.systemBlue
        appearance.titleTextAttributes = [.foregroundColor: UIColor.white]
        navigationItem.standardAppearance = appearance
        navigationItem.scrollEdgeAppearance = appearance
        navigationItem.compactAppearance = appearance

这就是结果

记住将检查器中的所有设置设置为默认值。如果你需要更多的调整，搜索开发者文档“自定义你的应用程序的导航栏”

希望这能有所帮助。

SWIFT 4 -平滑过渡(最佳解决方案):

如果你从导航控制器向后移动你必须在你想要使用的导航控制器上设置不同的颜色

override func willMove(toParentViewController parent: UIViewController?) {
    navigationController?.navigationBar.barTintColor = .white
    navigationController?.navigationBar.tintColor = Constants.AppColor
}

而不是把它放在viewWillAppear中，这样转换就更干净了。

斯威夫特4.2

override func willMove(toParent parent: UIViewController?) {
    navigationController?.navigationBar.barTintColor = UIColor.black
    navigationController?.navigationBar.tintColor = UIColor.black
}