title: Python - Kivy: Change Spinner Options size color
body: <p>I'm looking for a way to change the color/ background and size of the options/ buttons that are shown within my spinner widget in kivy. I've read that the dropdown_buttons are defined in the option_cls. My spinners are defined in the .kv file and look like this:</p>
  
  <pre><code>Spinner:
     id: select_letter
     text: "Choose a letter"
     values: ('A', 'B', 'C')
     background_normal: 'graphics/buttons/dropdown_green.png'
     background_down: 'graphics/buttons/dropdown_blue.png'
     on_text:
        root.set_values()
  </code></pre>
  
  <p>How can I change the properties of the spinner options while keeping my spinner defined in kivy? Is there a way to directly change the size and background of it in the kv? Thanks!</p>