title: How to change radio's inactive color in Flutter?
body: <p>I have a <code>Radio</code> button inside a <code>ListTile</code>. When the <code>ListTile</code> is clicked, I change the <code>Radio</code>'s value. I don't want the radio to be clickable, so I don't provide an <code>onChanged</code> callback:</p>
  
  <pre><code>ListTile(
    onTap: () =&gt; onChanged(template.id),
    leading: Radio(
      value: template.id,
      groupValue: checkedId,
    )
    ...
  )
  </code></pre>
  
  <p>Doing that, the <code>Radio</code> becomes "inactive" and changes it's color to grey.
  The <code>Radio</code> has an <code>activeColor</code> property, but not for inactive.</p>
  
  <p>If I provide a dummy function to <code>Radio</code>'s <code>onChanged</code> property - it becomes active, but the problem is I don't want it to be clickable, I want the <code>ListTile</code> to be clickable only (the reason is - I want to be able to uncheck the <code>Radio</code>)</p>
  
  <p>Also, I only want to change the inactive color of those specific <code>Radio</code> buttons, and not for the whole app.</p>
  
  <p>Current Result:</p>
  
  <p><a href="https://i.stack.imgur.com/RR1s9.gif" rel="noreferrer"><img src="https://i.stack.imgur.com/RR1s9.gif" alt="Demo 1"></a></p>
  
  <p>Result with <code>onChange</code> (I can't uncheck the radio when clicking on it):</p>
  
  <p><a href="https://i.stack.imgur.com/Ss9L3.gif" rel="noreferrer"><img src="https://i.stack.imgur.com/Ss9L3.gif" alt="Demo 2"></a></p>