Why doesn't the button in xml change color?

Question

Kotlin

My problem is this. I want my button to be black with a white stroke.
I made a separate xml file where I wrote everything.

<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:innerRadius="0dp"
    android:shape="ring"
    android:thicknessRatio="2"
    android:useLevel="false" >

    <solid android:color="@android:color/black" />

    <stroke
        android:width="5dp"
        android:color="@android:color/white" />
</shape>

Further I try to apply all this in floatingActionBar. The stroke works but the default color of the button remains green.

<LinearLayout
    android:id="@+id/fabWrapper"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:background="@drawable/button_background"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintLeft_toLeftOf="parent"
    android:padding="5dp">

    <com.google.android.material.floatingactionbutton.FloatingActionButton
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

</LinearLayout>

My guess is that something in the view hierarchy is preventing me from setting my color.
How can I fix this?

<resources xmlns:tools="http://schemas.android.com/tools">
    <!-- Base application theme. -->
    <style name="Theme.QuitSmoking" parent="Theme.MaterialComponents.DayNight.DarkActionBar">
        <item name="colorPrimary">@color/purple_500</item>
        <item name="colorPrimaryVariant">@color/purple_700</item>
        <item name="colorOnPrimary">@color/white</item>
        <item name="colorSecondary">@color/teal_200</item>
        <item name="colorSecondaryVariant">@color/teal_700</item>
        <item name="colorOnSecondary">@color/black</item>
        <item name="android:statusBarColor" tools:targetApi="l">?attr/colorPrimaryVariant</item>
    </style>

    <style name="Theme.QuitSmoking.NoActionBar">
        <item name="windowActionBar">false</item>
        <item name="windowNoTitle">true</item>
    </style>

    <style name="Theme.QuitSmoking.AppBarOverlay" parent="ThemeOverlay.AppCompat.Dark.ActionBar" />

    <style name="Theme.QuitSmoking.PopupOverlay" parent="ThemeOverlay.AppCompat.Light" />
</resources>

Answer 1

I solved the problem. Removing all the themes created by the studio. They didn't let me set the color

Answer 2

So you set the background not to the button, but to the linear layout in which it lies for some reason. Set button.