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)

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
}

appearance()函数并不总是适用于我。所以我更喜欢创建一个NC对象并改变它的属性。

var navBarColor = navigationController!.navigationBar
navBarColor.barTintColor =
    UIColor(red:  255/255.0, green: 0/255.0, blue: 0/255.0, alpha: 100.0/100.0)
navBarColor.titleTextAttributes =
    [NSForegroundColorAttributeName: UIColor.whiteColor()]

此外，如果你想添加一个图像而不仅仅是文本，这也是可行的

var imageView = UIImageView(frame: CGRect(x: 0, y: 0, width: 70, height: 70))
imageView.contentMode = .ScaleAspectFit

var image = UIImage(named: "logo")
imageView.image = image
navigationItem.titleView = imageView

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
    } 

Swift 4, iOS 12和Xcode 10更新

只需在viewDidLoad()中放入一行

navigationController?.navigationBar.barTintColor = UIColor.red

在Swift 4中

您可以更改导航栏的颜色。只需在viewDidLoad()中使用下面的代码片段

导航栏颜色

self.navigationController?.navigationBar.barTintColor = UIColor.white

导航栏文字颜色

self.navigationController?.navigationBar.titleTextAttributes = [NSAttributedStringKey.foregroundColor: UIColor.purple]

对于iOS 11大标题导航栏，你需要使用largeTitleTextAttributes属性

self.navigationController?.navigationBar.largeTitleTextAttributes = [NSAttributedStringKey.foregroundColor: UIColor.purple]