UISearchBar search text color , background color swift 3

let textFieldInsideSearchBar = yourSearchbar.value(forKey: "searchField") as? UITextField

textFieldInsideSearchBar?.textColor = yourcolor

for subView in searchController.searchBar.subviews {

    for subViewOne in subView.subviews {

        if let textField = subViewOne as? UITextField {

           subViewOne.backgroundColor = UIColor.red

           //use the code below if you want to change the color of placeholder
           let textFieldInsideUISearchBarLabel = textField.value(forKey: "placeholderLabel") as? UILabel
                textFieldInsideUISearchBarLabel?.textColor = UIColor.blue
        }
     }
}

Swift 2.3

extension UISearchBar {

 var textColor:UIColor? {

     get {

         if let textField = self.valueForKey("searchField") as? UITextField  {

             return textField.textColor

         } else {

             return nil

         }

     }

     set (newValue) {

         if let textField = self.valueForKey("searchField") as? UITextField  {

             textField.textColor = newValue

         }

     }

 }

}