Notification Bar is grey after implementing Nav Dr

I am trying to learn implementations of Navigation Drawer in Android.

In one activity, i have made the Navigation Drawer come under the Status Bar(transparent) and over the App Bar and everything works fine.(left Screenshot)

In another activity in the same App, i am trying to create Navigation Drawer that pulls up under the App Bar. But here, the status bar turns grey for some reason(whether nav drawer is open or closed)(Right Screenshot). Other than this, everything seems fine.

Below is the screenshot:

The green Nav Drawer is a fragment.

What i want to know is how to make the status normal(darker shade of. Please remember, if i click that twin arrow icon in the App Bar, it will take me to another activity which contains another Nav Drawer which works like the one in Material Design(Full height of the screen and comes under a transparent Status Bar). This is shown in the left side of the screenshot.

Below is the code:

MainActivity.java:

public class MainActivity extends ActionBarActivity {
    Toolbar toolbar;
    DrawerLayout xDrawerLayout;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_alt);

        toolbar = (Toolbar) findViewById(R.id.app_bar);
        setSupportActionBar(toolbar);
        getSupportActionBar().setDisplayShowHomeEnabled(true);

        xDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
        xDrawerLayout.setStatusBarBackgroundColor(getResources().getColor(R.color.primary_dark));

        NavDrawerFragment mfragment = (NavDrawerFragment) getFragmentManager().findFragmentById(R.id.nav_drawer_fragment);
        mfragment.SetUp(xDrawerLayout, toolbar, R.id.nav_drawer_fragment);
    }
...

activity_alt.xml:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true"
    android:orientation="vertical">

    <include
        android:id="@+id/app_bar"
        layout="@layout/app_bar" />


    <android.support.v4.widget.DrawerLayout
        android:id="@+id/drawer_layout"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent">

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="@string/hello_world" />

        </RelativeLayout>

        <fragment
            android:id="@+id/nav_drawer_fragment"
            android:name="com.rt.droid.mattest.NavDrawerFragment"
            android:layout_width="@dimen/nav_drawer_width"
            android:layout_height="match_parent"
            android:layout_gravity="start"
            tools:layout="@layout/fragment_nav_drawer" />


    </android.support.v4.widget.DrawerLayout>

</LinearLayout>

NavDrawerFragment.java:

public class NavDrawerFragment extends Fragment {

    private ActionBarDrawerToggle mDrawerToggle;
    private DrawerLayout mDrawerLayout;
    public DrawerLearner yDrawerLearner;

    public NavDrawerFragment() {
        // Required empty public constructor
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View fView = inflater.inflate(R.layout.fragment_nav_drawer, container, false);
        //fView.setFitsSystemWindows(true);
        fView.setBackgroundColor(getResources().getColor(R.color.accent));
        return fView;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
    }

    public void SetUp(DrawerLayout drawerLayout, Toolbar toolbar, int frag_id) {
        this.mDrawerLayout = drawerLayout;
        View drawerFrag = getActivity().findViewById(frag_id);
        mDrawerToggle = new ActionBarDrawerToggle(getActivity(), mDrawerLayout, toolbar, R.string.drawer_open, R.string.drawer_close) {
            @Override
            public void onDrawerOpened(View drawerView) {
                super.onDrawerOpened(drawerView);
                getActivity().invalidateOptionsMenu();
            }

            @Override
            public void onDrawerClosed(View drawerView) {
                super.onDrawerClosed(drawerView);
                getActivity().invalidateOptionsMenu();
            }
        };

        yDrawerLearner = new DrawerLearner(mDrawerLayout, drawerFrag, getActivity());
        yDrawerLearner.execute();

        this.mDrawerLayout.setDrawerListener(mDrawerToggle);
        mDrawerLayout.setStatusBarBackgroundColor(getResources().getColor(R.color.primary_dark));

        mDrawerLayout.post(new Runnable() {
            @Override
            public void run() {
                mDrawerToggle.syncState();
            }
        });

    }
}

fragment_nav_drawer.xml:

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.rt.droid.mattest.NavDrawerFragment">

    <!-- TODO: Update blank fragment layout -->
    <TextView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:text="@string/hello_blank_fragment" />

</FrameLayout>

app_bar.xml:

<android.support.v7.widget.Toolbar xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="@color/primary"
    app:popupTheme="@style/AppTheme.PopupMenu"
    android:theme="@style/AppTheme.Toolbar">

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

styles.xml:

<resources>

    <!-- Base application theme. -->
    <style name="AppTheme" parent="AppTheme.Base">
        <!-- Customize your theme here. -->
    </style>

    <style name="AppTheme.Base" parent="Theme.AppCompat.Light.NoActionBar">
        <item name="colorPrimary">@color/primary</item>
        <item name="colorPrimaryDark">@color/primary_dark</item>
        <item name="colorAccent">@color/accent</item>
    </style>

    <style name="AppTheme.Toolbar" parent="ThemeOverlay.AppCompat.Dark">
        <item name="android:textColorPrimary">@color/primary_text</item>
        <item name="android:textColorSecondary">@color/accent</item>
    </style>

    <style name="AppTheme.PopupMenu" parent="ThemeOverlay.AppCompat.Dark">
        <item name="android:background">@color/accent</item>
    </style>

</resources>

styles.xml(v21):

<resources>
    <style name="AppTheme" parent="AppTheme.Base">
        <!-- Customize your theme here. -->
        <item name="android:colorPrimary">@color/primary</item>
        <item name="android:colorPrimaryDark">@color/primary_dark</item>
        <item name="android:colorAccent">@color/accent</item>
        <item name="android:windowDrawsSystemBarBackgrounds">true</item>
        <item name="android:statusBarColor">@android:color/transparent</item>
        <item name="android:windowTranslucentStatus">true</item>
    </style>

</resources>

Colors.xml(screenshot showing color samples):

Note: I do not want to compromise on the styles etc that would render my other navigation drawer not working. In other words, i prefer a solution wherein both types of navigation bar works as expected in the same app.

Please let me know if you need any info and i shall edit if required. Edit: added app_bar.xml & colors.xml for clarity.

But here, the status bar turns grey for some reason

It's the translucent (25% black) status bar background over the white background of activity underneath it.

What i want to know is how to make the status normal

You need to disable translucent status bar for the second activity. It is activated by this line in your theme definition:

<item name="android:windowTranslucentStatus">true</item>
<item name="android:statusBarColor">@color/primary_dark</item>

So either define a child theme and override the flag with false or clear the flag programmatically by calling this from your activity:

if (Build.VERSION.SDK_INT >= 21) {
    getWindow().clearFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
    getWindow().setStatusBarColor(getResources().getColor(R.color.primary_dark);
}