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)

Swift 5 (iOS 14)

全导航栏定制。

// -----------------------------------------------------------
// NAVIGATION BAR CUSTOMIZATION
// -----------------------------------------------------------
self.navigationController?.navigationBar.prefersLargeTitles = true
self.navigationController?.navigationBar.tintColor = UIColor.white
self.navigationController?.navigationBar.isTranslucent = false

if #available(iOS 13.0, *) {
    let appearance = UINavigationBarAppearance()
    appearance.configureWithDefaultBackground()
    appearance.backgroundColor = UIColor.blue
    appearance.largeTitleTextAttributes = [NSAttributedString.Key.foregroundColor: UIColor.white]
    appearance.titleTextAttributes = [NSAttributedString.Key.foregroundColor: UIColor.white]

    navigationController?.navigationBar.standardAppearance = appearance
    navigationController?.navigationBar.scrollEdgeAppearance = appearance
    navigationController?.navigationBar.compactAppearance = appearance

} else {
    self.navigationController?.navigationBar.barTintColor = UIColor.blue
    self.navigationController?.navigationBar.largeTitleTextAttributes = [NSAttributedString.Key.foregroundColor: UIColor.white]
    self.navigationController?.navigationBar.titleTextAttributes = [NSAttributedString.Key.foregroundColor: UIColor.white]
}

// -----------------------------------------------------------
// NAVIGATION BAR SHADOW
// -----------------------------------------------------------
self.navigationController?.navigationBar.layer.masksToBounds = false
self.navigationController?.navigationBar.layer.shadowColor = UIColor.black.cgColor
self.navigationController?.navigationBar.layer.shadowOffset = CGSize(width: 0, height: 2)
self.navigationController?.navigationBar.layer.shadowRadius = 15
self.navigationController?.navigationBar.layer.shadowOpacity = 0.7

如果你使用iOS 13或14和大标题，并想改变导航栏的颜色，使用以下代码:

参考barTintColor不适用时导航栏是大标题

    fileprivate func setNavigtionBarItems() {
        if #available(iOS 13.0, *) {
            let appearance = UINavigationBarAppearance()
            appearance.configureWithDefaultBackground()
            appearance.backgroundColor = .brown
//            let naviFont = UIFont(name: "Chalkduster", size: 30) ?? .systemFont(ofSize: 30)
//            appearance.titleTextAttributes = [NSAttributedString.Key.font: naviFont]
            
            navigationController?.navigationBar.prefersLargeTitles = true
            navigationController?.navigationBar.standardAppearance = appearance
            navigationController?.navigationBar.scrollEdgeAppearance = appearance
            //navigationController?.navigationBar.compactAppearance = appearance
        } else {
            // Fallback on earlier versions
            navigationController?.navigationBar.barTintColor = .brown
        }
    }

这花了我1个小时来找出我的代码中的错误:(，因为我使用大标题，很难用largeTitle改变tintColor，为什么苹果让它这么复杂，这么多行只是做一个tintColor的navigationBar。

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)

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
}

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
    }