Toolbar behaving really strangely

Question

In my app I have two activities right now. The first one, LoginActivity, has Theme.AppCompat.Light.DarkActionBar as its theme. The other one, ClientesActivity, has an <item name="windowActionBar">false</item> and a custom android.support.v7.widget.Toolbar. They used to behave correctly. When I updated to Build Tools 27.0.1, Gradle 3.0.1 and Support Library 27.0.2, they all started looking like this:

LoginActivity

ClientesActivity

Here's the code:

styles.xml

<resources>
    <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
        <item name="android:background">#FAFAFA</item>
        <item name="colorPrimary">@color/colorPrimary</item>
        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
        <item name="colorAccent">@color/colorAccent</item>

    </style>

    <style name="AppThemeNoBar" parent="AppTheme">
        <item name="windowActionBar">false</item>
        <item name="windowNoTitle">true</item>
    </style>
</resources>

clientes_activity.xml

<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:id="@+id/coordinator"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:theme="@style/AppThemeNoBar"
    tools:context="melamed.soldeloesteapp.ClientesActivity">

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

        <android.support.design.widget.AppBarLayout
            android:id="@+id/tb_clientes"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">

            <android.support.v7.widget.Toolbar xmlns:app="http://schemas.android.com/apk/res-auto"
                android:id="@+id/toolbar_clientes"
                android:layout_width="match_parent"
                android:layout_height="?attr/actionBarSize"
                android:background="?attr/colorPrimary"
                android:minHeight="?attr/actionBarSize"
                app:layout_scrollFlags="scroll|enterAlways"
                app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
                app:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
                app:title="Carrito">

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

        <!-- Some more irrelevant stuff -->

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

Please someone tell me how to fix them back!

PS: They were blue and with white text, as any toolbar (the custom one had white buttons).

Answer 1

OK, I found the solution by myself while removing stuff. I discovered that from some support library version, android:background in a style affects only the Toolbar (WTF?). I removed the <item name="android:background">#FAFAFA</item> and it worked. Now, how can I default a background colour from a theme? (Answer in the comments, cba to make a whole new question about this)