Проблемы с изменением цвета кнопки в viewPager2 в Android

Элемент, который выполняется при запуске activity

 setContentView(R.layout.activity_test); //запускаем фронтенд
        setTitle(group);

        ViewPager2 pager=(ViewPager2)findViewById(R.id.pager);
        FragmentStateAdapter pageAdapter = new MyAdapter(this);
        pager.setAdapter(pageAdapter);

        LayoutInflater factory = this.getLayoutInflater();
        pager_view = factory.inflate(R.layout.fragment_page, null); //Получаем элементы во fragment_page


        switch (commonStuff.getNowCalendar()
        .get(Calendar.DAY_OF_WEEK)){ //запускаем расписание на текущий день
            case Calendar.MONDAY:
                loadDay(pager_view.findViewById(R.id.mondayButton));
                break;
            case Calendar.TUESDAY:
                loadDay(pager_view.findViewById(R.id.tuesdayButton));
                break;
            case Calendar.WEDNESDAY:
                loadDay(pager_view.findViewById(R.id.wednesdayButton));
                break;
            case Calendar.THURSDAY:
                loadDay(pager_view.findViewById(R.id.thursdayButton));
                break;
            case Calendar.FRIDAY:
                loadDay(pager_view.findViewById(R.id.fridayButton));
                break;
            case Calendar.SATURDAY:
                loadDay(pager_view.findViewById(R.id.saturdayButton));
                break;
            case Calendar.SUNDAY:
                loadDay(pager_view.findViewById(R.id.sundayButton));
                break;
        }

Сам метод, который должен менять цвет:

   public void loadDay(View view){
        LinearLayout parent = pager_view.findViewById(R.id.DAYS);
        for(int i=0; i<parent.getChildCount();i++){
            Button child = (Button) parent.getChildAt(i);
//Время костылей
            ViewGroup.LayoutParams lp = child.getLayoutParams();
            lp.width = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 46, getResources().getDisplayMetrics()); //установка ширины и высоты в dp
            lp.height = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 38, getResources().getDisplayMetrics());
            child.setTextSize((float) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_PX, 15, getResources().getDisplayMetrics()));
            child.setBackgroundColor(Color.LTGRAY);
            child.setLayoutParams(lp);
        }

        view.setBackgroundColor(Color.DKGRAY);

Сам layout с кнопками

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        xmlns:app="http://schemas.android.com/apk/res-auto">
    <LinearLayout
            android:layout_width="wrap_content"
            android:layout_height="50dp"
            android:id="@+id/DAYS"
            android:layout_marginTop="5dp"
            app:layout_constraintTop_toBottomOf="@+id/header_group"
            app:layout_constraintLeft_toLeftOf="parent"
            app:layout_constraintRight_toRightOf="parent"
    >
        <Button
                android:id="@+id/mondayButton"
                android:onClick="loadDay"
                android:text="@string/monday"
                android:textSize="15sp"
                style="@style/DaysButtonStyle"
                app:layout_constraintLeft_toLeftOf="parent"
                app:layout_constraintRight_toLeftOf="@+id/tuesdayButton"
                app:layout_constraintTop_toBottomOf="@+id/header_group"
        />

        <Button
                android:id="@+id/tuesdayButton"
                android:text="@string/tuesday"
                android:textSize="15sp"
                android:onClick="loadDay"
                style="@style/DaysButtonStyle"
                app:layout_constraintLeft_toRightOf="@+id/mondayButton"
                app:layout_constraintRight_toLeftOf="@+id/wednesdayButton"

                app:layout_constraintTop_toBottomOf="@+id/header_group"/>

        <Button
                android:id="@+id/wednesdayButton"
                android:text="@string/wednesday"
                android:onClick="loadDay"
                android:textSize="15sp"
                style="@style/DaysButtonStyle"
                app:layout_constraintLeft_toRightOf="@+id/tuesdayButton"
                app:layout_constraintRight_toLeftOf="@+id/thursdayButton"
                app:layout_constraintTop_toBottomOf="@+id/header_group"
        />
        <Button
                android:id="@+id/thursdayButton"
                android:text="@string/thursday"
                android:onClick="loadDay"
                android:textSize="15sp"
                style="@style/DaysButtonStyle"
                app:layout_constraintLeft_toRightOf="@+id/wednesdayButton"
                app:layout_constraintRight_toLeftOf="@+id/fridayButton"
                app:layout_constraintTop_toBottomOf="@+id/header_group"
        />
        <Button
                android:id="@+id/fridayButton"
                android:text="@string/friday"
                android:onClick="loadDay"
                android:textSize="15sp"
                style="@style/DaysButtonStyle"
                app:layout_constraintLeft_toRightOf="@+id/thursdayButton"
                app:layout_constraintRight_toLeftOf="@+id/saturdayButton"
                app:layout_constraintTop_toBottomOf="@+id/header_group"/>

        <Button
                android:id="@+id/saturdayButton"
                style="@style/DaysButtonStyle"
                android:text="@string/sunday"
                android:onClick="loadDay"
                android:textSize="15sp"
                app:layout_constraintLeft_toRightOf="@+id/fridayButton"
                app:layout_constraintRight_toLeftOf="@+id/sundayButton"
                app:layout_constraintTop_toBottomOf="@+id/header_group"
        />
        <Button android:id="@+id/sundayButton"
                android:layout_width="46dp"
                android:layout_height="38dp"
                android:text="ВС"
                android:onClick="loadDay"
                android:textSize="15sp"
                app:layout_constraintLeft_toRightOf="@+id/saturdayButton"
                app:layout_constraintTop_toBottomOf="@+id/headergroup"
        />
    </LinearLayout>


</androidx.constraintlayout.widget.ConstraintLayout>

После запуска программы: Цвет не поменялся. Как решить эту проблему? При нажатии непосредственно на кнопку - все работает. Необходимо, чтобы при запуске программы без нажатия на саму кнопку менялся цвет.