How to remove the shadow above the app bar?

I believe this question is pointing to same problem Android appbarlayout elevation appears in status bar

Possible solutions:

Your root layout should have android:fitsSystemWindows="true" at all times, otherwise your UI will not draw behind status bar.

Now wrap the AppBarLayout inside another CoordinatorLayout which has

android:fitsSystemWindows="false".

This will prevent the shadow from overflowing into statusbar.

Add elevation 0dp to AppBarLayout

<android.support.design.widget.AppBarLayout
android:id="@+id/app_bar_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:elevation="0dp">

Call below method in the onCreate of your activity with the desired status bar color.

public void changeStatusBarColor(String hexColor)
  {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
        Window window = getWindow();
        window.addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);
        window.setStatusBarColor(Color.parseColor("#AD2525"));
    }
 }

XML

<?xml version="1.0" encoding="utf-8"?><android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:context="com.example.bharath.myapplication.MainActivity">

<android.support.design.widget.AppBarLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:theme="@style/AppTheme.AppBarOverlay">

    <android.support.v7.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"
        android:background="?attr/colorPrimary"
        app:popupTheme="@style/AppTheme.PopupOverlay" />

</android.support.design.widget.AppBarLayout>

<RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#AD2525"
    app:layout_behavior="@string/appbar_scrolling_view_behavior">
    <!--
    Other views
    -->

</RelativeLayout></android.support.design.widget.CoordinatorLayout>

Result