Android - CardView backgroundcolor tiempo ejecución

<?xml version="1.0" encoding="utf-8"?>

<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:card_view="http://schemas.android.com/apk/res-auto"

    xmlns:cardView="http://schemas.android.com/tools"

    android:id="@+id/idCardView"

    android:orientation="horizontal"

    android:layout_width="match_parent"

    android:layout_margin="8dp"

    android:layout_height="match_parent"

    card_view:cardBackgroundColor="#00CED1">

    <LinearLayout

        android:orientation="vertical"

        android:layout_width="match_parent"

        android:layout_height="wrap_content">

        <TextView

            android:id="@+id/txtTitle"

            android:padding="10dp"

            android:layout_width="match_parent"

            android:textStyle="bold"

            android:textSize="15dp"

            android:textColor="@android:color/black"

            android:layout_height="wrap_content" />

    </LinearLayout>

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

public class MainActivity extends AppCompatActivity {

    ListView lvList;

    ArrayList<ListData> myList = new ArrayList<ListData>();

    ListAdapter listAdapter;

    CardView cardView;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);

        setSupportActionBar(toolbar);

        lvList = (ListView) findViewById(R.id.lvList);

        listAdapter = new ListAdapter(MainActivity.this, myList);

        lvList.setAdapter(listAdapter);

        cardView = (CardView) findViewById(R.id.idCardView);

        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);

        fab.setOnClickListener(new View.OnClickListener() {

            @Override

            public void onClick(View view) {

                ListData mLog = new ListData();

                mLog.setTitle("titulo");

                mLog.setDescription("descripcion");

                cardView.setCardBackgroundColor(Color.parseColor("#AAAAAA"));

                myList.add(0, mLog);

                listAdapter.notifyDataSetChanged();

            }

        });

    }