title: How to change the background color of a JSpinner (Number model)?
body: <p>I want to change the background color of my <code>JSpinner</code> in red to notify the user an error. My spinner use a number model (no idea if it influence).
  I tried a lot of solutions but no one worked.</p>
  <pre><code>jspinner.setBackground(Color.red);
  jspinner.getEditor().getComponent(0).setBackground(Color.red);
  </code></pre>
  <p>I understood that I have to access to a specific component of the spinner (like a <code>JFormattedTextField</code>) but I don't know how to do...)</p>
  <h2>Edit</h2>
  <p>This should work:</p>
  <pre><code>JSpinner.NumberEditor jsEditor = (JSpinner.NumberEditor) 
  spinner.getEditor(); jsEditor.getTextField().setBackground(Color.red);
  </code></pre>
  <p>But it doesn't. Anybody has an idea why?</p>