每个（默认）选项卡栏项均由文本和图标组成。通过指定外观可以很容易地全局更改文本颜色：

// you can add this code to you AppDelegate application:didFinishLaunchingWithOptions: 
// or add it to viewDidLoad method of your TabBarController class
UITabBarItem.appearance().setTitleTextAttributes([NSForegroundColorAttributeName: UIColor.magentaColor()], forState:.Normal)
UITabBarItem.appearance().setTitleTextAttributes([NSForegroundColorAttributeName: UIColor.redColor()], forState:.Selected)

对于图像，情况要复杂一些。您不能全局定义它们的外观。您应该在TabBarController类中重新定义它们。将下面的代码添加到viewDidLoad您的TabBarController类的方法中：

for item in self.tabBar.items as [UITabBarItem] {
    if let image = item.image {
        item.image = image.imageWithColor(UIColor.yellowColor()).imageWithRenderingMode(.AlwaysOriginal)
    }
}

众所周知imageWithColor(...)，UIImage类中没有方法。所以这是扩展实现：

// Add anywhere in your app
extension UIImage {
    func imageWithColor(tintColor: UIColor) -> UIImage {
        UIGraphicsBeginImageContextWithOptions(self.size, false, self.scale)

        let context = UIGraphicsGetCurrentContext() as CGContextRef
        CGContextTranslateCTM(context, 0, self.size.height)
        CGContextScaleCTM(context, 1.0, -1.0);
        CGContextSetBlendMode(context, .Normal)

        let rect = CGRectMake(0, 0, self.size.width, self.size.height) as CGRect
        CGContextClipToMask(context, rect, self.CGImage)
        tintColor.setFill()
        CGContextFillRect(context, rect)

        let newImage = UIGraphicsGetImageFromCurrentImageContext() as UIImage
        UIGraphicsEndImageContext()

        return newImage
    }
}