В Swift 4.1 и Xcode 9.4.1
//Displaying alert with multiple actions and custom font ans size
let alert = UIAlertController(title: "", message: "", preferredStyle: .alert)
let titFont = [NSAttributedStringKey.font: UIFont(name: "ArialHebrew-Bold", size: 15.0)!]
let msgFont = [NSAttributedStringKey.font: UIFont(name: "Avenir-Roman", size: 13.0)!]
let titAttrString = NSMutableAttributedString(string: "Title Here", attributes: titFont)
let msgAttrString = NSMutableAttributedString(string: "Message Here", attributes: msgFont)
alert.setValue(titAttrString, forKey: "attributedTitle")
alert.setValue(msgAttrString, forKey: "attributedMessage")
let action1 = UIAlertAction(title: "Action 1", style: .default) { (action) in
print("\(String(describing: action.title))")
}
let action2 = UIAlertAction(title: "Action 2", style: .default) { (action) in
print("\(String(describing: action.title))")
}
let okAction = UIAlertAction(title: "Ok", style: .default) { (action) in
print("\(String(describing: action.title))")
}
alert.addAction(action1)
alert.addAction(action2)
alert.addAction(okAction)
alert.view.tintColor = UIColor.blue
alert.view.layer.cornerRadius = 40
// //If required background colour
// alert.view.backgroundColor = UIColor.white
DispatchQueue.main.async(execute: {
self.present(alertController, animated: true)
})