NavigationBarTheme.swift

import Foundation

extension UIViewController {
    func st_setNavigationBarTheme() {
        if let nav = self.navigationController?.navigationBar {
            // Colors
            nav.translucent = false
            nav.barTintColor = UIColor.whiteColor() // themeColor
            nav.titleTextAttributes = [
                NSForegroundColorAttributeName: UIColor.whiteColor()
            ]

            // Remove shadow
            let img = UIImage()
            nav.shadowImage = img
            nav.setBackgroundImage(img, forBarMetrics: UIBarMetrics.Default)
        }
    }
}