问如何更改UITableViewCell的蓝色突出显示颜色？

EN

let selectedView = UIView()
selectedView.backgroundColor = .white
cell.selectedBackgroundView = selectedView

let selectedView = UIView()
selectedView.backgroundColor = .white
UITableViewCell.appearance().selectedBackgroundView = selectedView

class AppDelegate: UIResponder, UIApplicationDelegate {

    //... truncated

   func application(application: UIApplication!, didFinishLaunchingWithOptions launchOptions: NSDictionary!) -> Bool {

        // set up your background color view
        let colorView = UIView()
        colorView.backgroundColor = UIColor.yellowColor()

        // use UITableViewCell.appearance() to configure 
        // the default appearance of all UITableViewCells in your app
        UITableViewCell.appearance().selectedBackgroundView = colorView

        return true
    }

    //... truncated
}

- (void)setSelected:(BOOL)selected animated:(BOOL)animated
{
    if(selected) {
        self.contentView.backgroundColor = UIColor.blueColor;
    } else {
        self.contentView.backgroundColor = UIColor.whiteColor;
    }
}