更新为Swift 3, 4, 4.2, 5+

// setup navBar.....
UINavigationBar.appearance().barTintColor = .black
UINavigationBar.appearance().tintColor = .white
UINavigationBar.appearance().titleTextAttributes = [NSForegroundColorAttributeName: UIColor.white]
UINavigationBar.appearance().isTranslucent = false

斯威夫特4

UINavigationBar.appearance().barTintColor = .black
UINavigationBar.appearance().tintColor = .white
UINavigationBar.appearance().titleTextAttributes = [NSAttributedStringKey.foregroundColor: UIColor.white]
UINavigationBar.appearance().isTranslucent = false

Swift 4.2, 5+

UINavigationBar.appearance().barTintColor = .black
UINavigationBar.appearance().tintColor = .white
UINavigationBar.appearance().titleTextAttributes = [NSAttributedString.Key.foregroundColor: UIColor.white]
UINavigationBar.appearance().isTranslucent = false

如果你想使用大标题，添加这一行:

UINavigationBar.navigationBar.prefersLargeTitles = true

也可以查看这里:https://github.com/hasnine/iOSUtilitiesSource

斯威夫特4:

在应用程序级别更改导航栏外观的完美代码。

// MARK: Navigation Bar Customisation

// To change background colour.
UINavigationBar.appearance().barTintColor = .init(red: 23.0/255, green: 197.0/255, blue: 157.0/255, alpha: 1.0)

// To change colour of tappable items.
UINavigationBar.appearance().tintColor = .white

// To apply textAttributes to title i.e. colour, font etc.
UINavigationBar.appearance().titleTextAttributes = [.foregroundColor : UIColor.white,
                                                    .font : UIFont.init(name: "AvenirNext-DemiBold", size: 22.0)!]
// To control navigation bar's translucency.
UINavigationBar.appearance().isTranslucent = false

编码快乐!

导航栏:

navigationController?.navigationBar.barTintColor = UIColor.green

用你想要的任何UIColor替换greenColor，如果你喜欢，你也可以使用RGB。

导航栏文本:

navigationController?.navigationBar.titleTextAttributes = [.foregroundColor: UIColor.orange]

用你喜欢的颜色替换orangeColor。

标签栏:

tabBarController?.tabBar.barTintColor = UIColor.brown

标签栏文本:

tabBarController?.tabBar.tintColor = UIColor.yellow

最后两个，用你选择的颜色替换brownColor和yellowColor。

在iOS 15中，UIKit扩展了scrollEdgeAppearance的使用，默认情况下它会生成透明的背景，用于所有导航栏。 设置scrollEdgeAppearance如下代码。

if #available(iOS 15, *) {
        let appearance = UINavigationBarAppearance()
        appearance.configureWithOpaqueBackground()
        appearance.backgroundColor = < your tint color >
        navigationController?.navigationBar.standardAppearance = appearance;
        navigationController?.navigationBar.scrollEdgeAppearance = navigationController?.navigationBar.standardAppearance
    } 

首先将navigationBar的isTranslucent属性设置为false以获得所需的颜色。然后像这样改变导航栏的颜色:

@IBOutlet var NavigationBar: UINavigationBar!

NavigationBar.isTranslucent = false
NavigationBar.barTintColor = UIColor (red: 117/255, green: 23/255, blue: 49/255, alpha: 1.0)

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。