Change the color of a swift menu button

I have the following code and the color of the menu button is white but I want to change its color and what I have tried has not worked yet.

I'd appreciate your help.

    func addSlideMenuButton(){
    //let image = UIImage(named: "menu-button2.png")
    let btnShowMenu = UIButton()
    btnShowMenu.setImage(self.defaultMenuImage(), for: UIControlState())
    btnShowMenu.frame = CGRect(x: 0, y: 0, width: 30, height: 30)
    btnShowMenu.addTarget(self, action: #selector(BaseViewController.onSlideMenuButtonPressed(_:)), for: UIControlEvents.touchUpInside)
    btnShowMenu.setTitleColor(UIColor.blue, for: UIControlState())
    btnShowMenu.tintColor = UIColor.blue
    //btnShowMenu.setBackgroundImage(image, for: UIControlState())
    let customBarItem = UIBarButtonItem(customView: btnShowMenu)
    self.navigationItem.leftBarButtonItem = customBarItem

    let back = UIBarButtonItem(title: "⏎", style: .plain, target: self, action: #selector(BaseViewController.backNavigationSim(_ :)))
    self.navigationItem.rightBarButtonItem = back


}