Solution 1:

Chances are you are extending from the wrong parent. If not, you can try adding the style to the toolbar layout directly, if you want to override the theme's settings.

In your toolbar layout:

 <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"
      android:layout_width="match_parent"
      android:layout_height="?attr/actionBarSize"
      android:minHeight="?attr/actionBarSize"
      app:theme="@style/ToolBarStyle"
      app:popupTheme="@style/ToolBarPopupStyle"
      android:background="@color/actionbar_color" />

In your styles:

 <!-- ToolBar -->
  <style name="ToolBarStyle" parent="Theme.AppCompat">
      <item name="android:textColorPrimary">@android:color/white</item>
      <item name="android:textColorSecondary">@android:color/white</item>
      <item name="actionMenuTextColor">@android:color/white</item>      
      <item name="actionOverflowButtonStyle">@style/ActionButtonOverflowStyle</item>
      <item name="drawerArrowStyle">@style/DrawerArrowStyle</item>
 </style>

Solution 2:

Add the following as toolbar.xml

<?xml version="1.0" encoding="utf-8"?>
<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"
    android:layout_height="wrap_content"
    android:layout_width="match_parent"
    android:fitsSystemWindows="true"
    android:minHeight="?attr/actionBarSize"
    app:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
    app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
    android:background="?attr/colorPrimary">

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

Then in the layout where you needed

<include layout="@layout/toolbar"/>

Enjoy

Solution 3:

Inside Activity, you can use

    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);
    toolbar.setTitleTextColor(getResources().getColor(android.R.color.white));

If you love to choose xml for both title color & back arrow white just add this style in style.xml .

 <style name="ToolBarStyle" parent="Theme.AppCompat">
    <item name="android:textColorPrimary">@android:color/white</item>
    <item name="android:textColorSecondary">@android:color/white</item>
    <item name="actionMenuTextColor">@android:color/white</item>
</style>

And toolbar look like :

 <android.support.v7.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        app:theme="@style/ToolBarStyle"
        android:layout_height="?attr/actionBarSize"
  />