title: How to Change CardView background color from a theme
body: <p>In an app that has multiple themes, how would you change the background color of the CardView from the styles file?</p>
  
  <p>styles.xml</p>
  
  <pre><code>&lt;style name="AppTheme1" parent="Theme.AppCompat.Light.DarkActionBar"&gt;
          &lt;item name="colorPrimary"&gt;@color/colorPrimaryTheme1&lt;/item&gt;
          &lt;item name="colorPrimaryDark"&gt;@color/colorPrimaryDarkTheme1&lt;/item&gt;
          &lt;item name="colorAccent"&gt;@color/colorAccentTheme1&lt;/item&gt;
  &lt;/style&gt;
  
  &lt;style name="AppTheme2" parent="Theme.AppCompat.Light.DarkActionBar"&gt;
          &lt;item name="colorPrimary"&gt;@color/colorPrimaryTheme2&lt;/item&gt;
          &lt;item name="colorPrimaryDark"&gt;@color/colorPrimaryDarkTheme2&lt;/item&gt;
          &lt;item name="colorAccent"&gt;@color/colorAccentTheme2&lt;/item&gt;
  &lt;/style&gt;
  
  &lt;style name="AppTheme3" parent="Theme.AppCompat.Light.DarkActionBar"&gt;
          &lt;item name="colorPrimary"&gt;@color/colorPrimaryTheme3&lt;/item&gt;
          &lt;item name="colorPrimaryDark"&gt;@color/colorPrimaryDarkTheme3&lt;/item&gt;
          &lt;item name="colorAccent"&gt;@color/colorAccentTheme3&lt;/item&gt;
  &lt;/style&gt;
  
  </code></pre>
  
  <p>CardView</p>
  
  <pre><code>&lt;androidx.cardview.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:app="http://schemas.android.com/apk/res-auto"
      android:id="@+id/cardView"
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      android:layout_marginStart="16dp"
      android:layout_marginTop="16dp"
      android:layout_marginEnd="16dp"
      android:elevation="4dp"
      app:cardCornerRadius="15dp"&gt;
  </code></pre>
  
  <p>I want to change the background color for each theme and I'm hoping to accomplish this in the styles.xml file.</p>