change view controller appearance swift code example

Example: swift change navigation bar color

// Navigation Bar:
navigationController?.navigationBar.barTintColor = UIColor.green

// Navigation Bar Text:
navigationController?.navigationBar.titleTextAttributes = [.foregroundColor: UIColor.orange]

// Tab Bar:
tabBarController?.tabBar.barTintColor = UIColor.brown

// Tab Bar Text:
tabBarController?.tabBar.tintColor = UIColor.yellow