Android Studio buttons wont change colour (will only use colours from themes.xml)

Question

I am fairly new to android studio and I am developing a small app.

I have just added my first buttons but I am having trouble selecting the colour of them. The code i am using in my activity xml is:

<Button
                android:id="@+id/signUpButton"

                android:text="SIGN UP"
                android:textColor="#FFF"
                android:textSize="30sp"
                android:layout_marginTop="20dp"
                android:layout_width="270dp"
                android:layout_height="60dp"
                android:background="@drawable/buttonshape"
                />

and the code in buttonshape.xml is:

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="rectangle" >
    <corners
        android:radius="14dp"
        />
    <solid
        android:color="#FCB1B1"
        />
    <padding
        android:left="0dp"
        android:top="0dp"
        android:right="0dp"
        android:bottom="0dp"
        />
    <size
        android:width="270dp"
        android:height="60dp"
        />
    <stroke
        android:width="3dp"
        android:color="#FCB1B1"
        />
</shape>

For some reason the button will not take on the colour specified in the buttonshape.xml and instead will take on the style from the themes.xml file

themes.xml:

<resources xmlns:tools="http://schemas.android.com/tools">
    <!-- Base application theme. -->
    <style name="Theme.Health_Link" parent="Theme.MaterialComponents.DayNight.DarkActionBar">
        <!-- Primary brand color. -->
        <item name="colorPrimary">@color/salmon</item>
        <item name="colorPrimaryVariant">#FFF</item>
        <item name="colorOnPrimary">@color/white</item>
        <!-- Secondary brand color. -->
        <item name="colorSecondary">@color/teal_200</item>
        <item name="colorSecondaryVariant">@color/teal_700</item>
        <item name="colorOnSecondary">@color/black</item>
        <!-- Status bar color. -->
        <item name="android:statusBarColor" tools:targetApi="l">?attr/colorPrimaryVariant</item>
        <!-- Customize your theme here. -->
        <item name="windowActionBar">false</item>
        <item name="windowNoTitle">true</item>

        <item name="android:windowContentTransitions">true</item>
        <item name="android:windowDisablePreview">true</item>
    </style>

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

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

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