title: WPF Checkbox style change
body: <p>I have just started with WPF and need specific feature for a checkbox:</p>
  
  <ol>
  <li>I want to change the shape from a box to a ellipse. </li>
  <li>Futher more there should be a color change (green = true, red = false) instead of cross. </li>
  </ol>
  
  <p>The background: I have different sensors and want to enable/disable them via these checkboxes. I also thought about to use buttons instead of checkboxes, but I think the function is more given by the checkboxes.</p>
  
  <p>I hope my description is understandable. Is it possible to define such a style- template? </p>
  
  <p>Kind regards </p>
  
  <p>Alex</p>