CardView provides a default elevation and corner radius so that cards have a consistent appearance across the platforms.

You can customize these default values using these attributes in the xml file:

  1. card_view:cardElevation attribute add elevation in CardView.
  2. card_view:cardBackgroundColor attribute is used to customize background color of CardView’s background(you can give any color).
  3. card_view:cardCornerRadius attribute is used to curve 4 edges of CardView
  4. card_view:contentPadding attribute add padding between card and children of card

Note: card_view is a namespace defined in topmost parent layout view. xmlns:card_view=“http://schemas.android.com/apk/res-auto”

Here an example:

<android.support.v7.widget.CardView
        xmlns:card_view="<http://schemas.android.com/apk/res-auto>"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        card_view:cardElevation="4dp"
        card_view:cardBackgroundColor="@android:color/white"
        card_view:cardCornerRadius="8dp"
        card_view:contentPadding="16dp">

        <!-- one child layout containing other layouts or views -->     

</android.support.v7.widget.CardView>

You can also do it programmatically using:

card.setCardBackgroundColor(....);
card.setCardElevation(...);
card.setRadius(....);
card.setContentPadding();

Check the official javadoc for additional properties.