title: Flutter Expansion Tile -- Header Color Change, and Trailing Animated Arrow Color Change
body: <p>I have used the Expansion Tile to generate a Expansion List View.
  I'm facing some customization issues in Expansion Tile Header.</p>
  
  <p>Below is my code.</p>
  
  <pre><code>ExpansionTile(           
      title: Container(
          child: Text(
              getCategory(i),
              style: TextStyle(
              color: Colors.white,
              ),
          ),
          color: Colors.black
      ),
  
      children: &lt;Widget&gt;[
          new Container(
              height: 60.0,
              margin: const EdgeInsets.only(top:10.0, left: 10.0, right:10.0, bottom: 10.0),
              decoration: BoxDecoration(                    
              color: Colors.blue,
              borderRadius: new BorderRadius.all(  Radius.circular(5.0) ),
              ),
          ),
          new Container(
              height: 60.0,
              margin: const EdgeInsets.only(top:10.0, left: 10.0, right:10.0, bottom: 0.0),
              decoration: BoxDecoration(                    
              color: Colors.green,
              borderRadius: new BorderRadius.all(  Radius.circular(5.0) ),
              ),
          )
      ],
      backgroundColor: Colors.white,
  )
  </code></pre>
  
  <p>I'm getting below result.</p>
  
  <p><a href="https://i.stack.imgur.com/hAS8w.png" rel="noreferrer"><img src="https://i.stack.imgur.com/hAS8w.png" alt="enter image description here"></a></p>
  
  <p>What I'm expecting to have is below.</p>
  
  <p><a href="https://i.stack.imgur.com/mdOCJ.png" rel="noreferrer"><img src="https://i.stack.imgur.com/mdOCJ.png" alt="enter image description here"></a></p>
  
  <p>If anyone know a workaround to customize the header color, please advice.</p>