mobile-app/android/app/src/main/res/values/styles.xml

<resources>

    <!-- Base application theme. -->
    <style name="AppTheme" parent="Theme.AppCompat.DayNight.NoActionBar">
        <!-- Customize your theme here. -->
        <item name="android:textColor">#000000</item>
    </style>

    <style name="BootTheme" parent="AppTheme">
        <item name="android:background">@drawable/bootsplash</item>
    </style>

</resources>