title: How do I change the background color of a button in Kivy?
body: <p>I am attempting to build a simple app that plays music every time a click on a button that I built in kivy. I would like to add graphics and styling, as the default color is just plain grey. How do I do I change that color to red? I have tried implementing the background_color parameter but that does not change anything. I have attached my code below:</p>
  
  <pre><code>   &lt;Test&gt;:
        do_default_tab: False
        Widget:
           canvas.before:
              Rectangle:
                  size: self.size
                  pos: self.pos
  
  
       TabbedPanelItem:
  
           text: 'Opera'
  
           text_size: self.size
  
  
           BoxLayout:
              orientation: 'vertical'
              padding: 20
              spacing: 10
  
              Button:
  
                 text: 'Nessun Dorma'
                 text_size: self.size
                 on_press: root.nessun_dorma()
  
  
                 halign: 'center'
                 valign: 'middle'
  
                 font_size: 20
  </code></pre>