How to change Toolbar home icon color

Here is what you are looking for. But this also changes the color of radioButton etc. So you might want to use a theme for it.

<item name="colorControlNormal">@color/colorControlNormal</item>

I solved it programmatically using this code:

final Drawable upArrow = getResources().getDrawable(R.drawable.abc_ic_ab_back_mtrl_am_alpha);
upArrow.setColorFilter(Color.parseColor("#FFFFFF"), PorterDuff.Mode.SRC_ATOP);
getSupportActionBar().setHomeAsUpIndicator(upArrow);

Revision 1:

Starting from API 23 (Marshmallow) the drawable resource abc_ic_ab_back_mtrl_am_alpha is changed to abc_ic_ab_back_material.

I solved it by editing styles.xml:

<style name="ToolbarColoredBackArrow" parent="AppTheme">
    <item name="android:textColorSecondary">INSERT_COLOR_HERE</item>
</style>

...then referencing the style in the Toolbar definition in the activity:

<LinearLayout
    android:id="@+id/main_parent_view"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <android.support.v7.widget.Toolbar
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        android:id="@+id/toolbar"
        app:theme="@style/ToolbarColoredBackArrow"
        app:popupTheme="@style/AppTheme"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:minHeight="?attr/actionBarSize"
        android:background="?attr/colorPrimary"/>