这个版本还删除了导航栏下的1px阴影线:

Swift 5:把这个放在你的AppDelegate didFinishLaunchingWithOptions中

UINavigationBar.appearance().barTintColor = UIColor.black
UINavigationBar.appearance().tintColor = UIColor.white
UINavigationBar.appearance().titleTextAttributes = [NSAttributedString.Key.foregroundColor: UIColor.white]
UINavigationBar.appearance().isTranslucent = false
UINavigationBar.appearance().setBackgroundImage(UIImage(), for: .any, barMetrics: .default)
UINavigationBar.appearance().shadowImage = UIImage()

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
}

确保将按钮状态设置为.normal

extension UINavigationBar {

    func makeContent(color: UIColor) {
        let attributes: [NSAttributedString.Key: Any]? = [.foregroundColor: color]

        self.titleTextAttributes = attributes
        self.topItem?.leftBarButtonItem?.setTitleTextAttributes(attributes, for: .normal)
        self.topItem?.rightBarButtonItem?.setTitleTextAttributes(attributes, for: .normal)
    }
}

ps iOS 12, Xcode 10.1

iOS 8 (swift)

let font: UIFont = UIFont(name: "fontName", size: 17)   
let color = UIColor.backColor()
self.navigationController?.navigationBar.topItem?.backBarButtonItem?.setTitleTextAttributes([NSFontAttributeName: font,NSForegroundColorAttributeName: color], forState: .Normal)

Swift 3和Swift 4兼容Xcode 9

一个更好的解决方案是为常见的导航栏创建一个类

我有5个控制器，每个控制器的标题都改为橙色。因为每个控制器都有5个导航控制器，所以我不得不从检查器或代码中改变每一个颜色。

所以我做了一个类，而不是改变每个导航栏从代码我只是分配这个类，它在所有5个控制器代码重用能力。 你只需要将这个类分配给每个控制器就可以了。

import UIKit

   class NabigationBar: UINavigationBar {
      required init?(coder aDecoder: NSCoder) {
       super.init(coder: aDecoder)
    commonFeatures()
 }

   func commonFeatures() {

    self.backgroundColor = UIColor.white;
      UINavigationBar.appearance().titleTextAttributes =     [NSAttributedStringKey.foregroundColor:ColorConstants.orangeTextColor]

 }


  }

UINavigationBar.appearance().barTintColor = UIColor(red: 46.0/255.0, green: 14.0/255.0, blue: 74.0/255.0, alpha: 1.0)
UINavigationBar.appearance().tintColor = UIColor.whiteColor()
UINavigationBar.appearance().titleTextAttributes = [NSForegroundColorAttributeName : UIColor.whiteColor()]

只需将这一行粘贴到代码中的didFinishLaunchingWithOptions中。