Conform this protocol, you can just use setRedNavBar() to set red background and white tintColor navigationBar.

RedBackNavProtocol.swift

import UIKit

protocol RedBackNavProtocol {
    func setRedNavBar()
}

extension RedBackNavProtocol where Self : UIViewController {
    func setRedNavBar() {
        self.navigationController?.navigationBar.barTintColor = UIColor.navigation_bar_red
        self.navigationController?.navigationBar.tintColor = UIColor.white
        self.navigationBar?.titleTextAttributes = [
            NSForegroundColorAttributeName: UIColor.white
        ]
    }
}