title: Change calendar button color for showDatePicker
body: <p>I'm using showDatePicker to display a calendar. How do I change the button color and also the today's date background color</p>
  
  <p><a href="https://i.stack.imgur.com/4ezcJ.jpg" rel="noreferrer"><img src="https://i.stack.imgur.com/4ezcJ.jpg" alt="enter image description here"></a></p>
  
  <p>I've tried different colors setting in Theme Data. but the OK, Cancel &amp; today's date still in blue</p>
  
  <pre><code>Theme(data: ThemeData(
        splashColor: Color(0xFFFE9BC0),
      )
      child: myWidget(),
  );
  </code></pre>