title: Flutter Card with Transparent Background
body: <p>I am trying to make my card transparent in order to show the thing in background.</p>
  
  <p>I had tries to set color property of card to transparent, but it is show gray kind of background with opacity.</p>
  
  <p><img src="https://i.stack.imgur.com/gP9PF.jpg" alt="Result"></p>
  
  <p>I also tries use white color with different opacity, but the result outcome is not pure white color with transparent.</p>
  
  <pre><code>   Card(
        color: Colors.transparent,
        child: Padding(
          padding: const EdgeInsets.all(16),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.stretch,
            children: &lt;Widget&gt;[
              CardLabelSmall("Current Premix Plan Document"),
              Expanded(child: PremixPlanDocList()),
              Row(
                children: &lt;Widget&gt;[
                  Expanded(
                    child: RaisedButton(
                      onPressed: () async {
                        homeBloc.retrieveCurrentMrfPremixPlan();
                      },
                      child: const Text("Retrieve Premix Plan"),
                    ),
                  ),
                ],
              ),
            ],
          ),
        ),
      );
  </code></pre>
  
  <p>other white color but still not white at all</p>
  
  <pre><code>color: Colors.white70,
  color: Colors.white54,
  color: Colors.white30,
  </code></pre>
  
  <p>How can I achieve to have a pure white background with transperant?</p>