Changing the color of the icons in a UItextField inside a UISearchBar

Here is the solution:

// Text field in search bar.
let textField = searchController.searchBar.value(forKey: "searchField") as! UITextField

let glassIconView = textField.leftView as! UIImageView
glassIconView.image = glassIconView.image?.withRenderingMode(.alwaysTemplate)
glassIconView.tintColor = UIColor.white

let clearButton = textField.valueForKey("clearButton") as! UIButton
clearButton.setImage(clearButton.imageView?.image?.withRenderingMode(.alwaysTemplate), for: .normal)
clearButton.tintColor = UIColor.white