app/src/main/res/values-v31/themes.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <!--System palette (Android 12+)-->
    <style name="CalendarAppThemeLightMonet" parent="Theme.AppCompat.Light.NoActionBar">
        <item name="colorPrimary">@android:color/system_accent1_500</item>
        <item name="colorPrimaryDark">@android:color/system_accent1_800</item>
        <item name="colorAccent">@android:color/system_accent2_500</item>
        <item name="light_dark">@color/bg_black</item>
        <item name="android:windowBackground">@android:color/system_neutral1_10</item>
        <item name="android:itemBackground">@android:color/system_neutral1_10</item>
        <item name="settings_titleText">?android:attr/textAppearanceLargeInverse</item>
        <item name="month_header_bgcolor">@color/month_other_bgcolor</item>
        <item name="agenda_general_bgcolor">@color/agenda_general_background_color</item>
        <item name="agenda_day_item_text_color">@color/agenda_day_item_text_color</item>
        <item name="edit_event_bgcolor">@android:color/system_neutral1_10</item>
        <item name="editEvent_small_color">@color/edit_event_small</item>
        <item name="recurrence_picker_bgcolor_up">@android:color/system_neutral1_10</item>
        <item name="recurrence_picker_bgcolor">@color/recurrence_picker_background</item>
        <item name="done_text_recurrence">@color/recurrence_done_text_color</item>
        <item name="spinner_privacy_presence_bgcolor">@color/spinner_privacy_popupBackground</item>
        <item name="event_info_bgcolor">@android:color/system_neutral1_10</item>
        <item name="event_info_scrollview_bgcolor">@android:color/system_neutral1_10</item>
        <item name="event_info_organizer_color">@color/event_info_organizer_color</item>
        <item name="event_info_description_color">@color/event_info_description_color</item>
        <item name="event_info_body_color">@color/event_info_body_color</item>
        <item name="event_info_label_color">@color/event_info_label_color</item>
        <item name="create_event_date_color">@color/create_event_date_color</item>
        <item name="calendar_owner_text_color">@color/calendar_owner_text_color</item>
        <item name="calendar_date_banner_bgcolor">@color/calendar_date_banner_background</item>
        <item name="app_bar_color">@android:color/system_accent1_500</item>
        <item name="autoCompleteTextViewStyle">@style/actionbar_cursor</item>
        <item name="minus_button">@drawable/ic_menu_remove_field_holo_light</item>
        <item name="ic_menu_email">@drawable/ic_menu_email_holo_light</item>
        <item name="calendar_future_bg_color">@color/calendar_future_bg_color</item>
        <item name="month_other_bgcolor">@color/month_other_bgcolor</item>
        <item name="settings_calendar_offline">@drawable/ic_sync_off_light</item>
        <item name="iconAboutAuthors">@android:color/black</item>
        <item name="iconAboutLicense">@android:color/black</item>
        <item name="iconSettingsAbout">@android:color/black</item>
        <item name="iconSettingsGeneral">@android:color/black</item>
        <item name="iconAddCalendar">@android:color/black</item>
        <item name="iconCalendarAccount">@android:color/black</item>
       <item name="calendarSpinnerDisabledTextColor">@color/calendar_item_disabled</item>
    </style>
    <style name="CalendarAppThemeDarkMonet" parent="Theme.AppCompat.NoActionBar">
        <item name="colorPrimary">@android:color/system_accent1_500</item>
        <item name="colorPrimaryDark">@android:color/system_accent1_900</item>
        <item name="colorAccent">@android:color/system_accent2_400</item>
        <item name="light_dark">@android:color/white</item>
        <item name="android:windowBackground">@android:color/system_neutral1_800</item>
        <item name="android:itemBackground">@android:color/system_neutral1_800</item>
        <item name="actionBarPopupTheme">@style/ThemeOverlay.AppCompat.Dark</item>
        <item name="settings_titleText">?android:attr/textAppearanceLarge</item>
        <item name="month_header_bgcolor">@color/month_bgcolor_dark</item>
        <item name="agenda_general_bgcolor">@color/agenda_general_background_color_dark</item>
        <item name="agenda_day_item_text_color">@color/agenda_day_item_text_color_dark</item>
        <item name="edit_event_bgcolor">@color/edit_event_color_dark</item>
        <item name="editEvent_small_color">@color/edit_event_small_dark</item>
        <item name="recurrence_picker_bgcolor_up">@color/recurrence_picker_background_up_dark</item>
        <item name="recurrence_picker_bgcolor">@color/recurrence_picker_background_dark</item>
        <item name="done_text_recurrence">@color/recurrence_done_text_color_black</item>
        <item name="spinner_privacy_presence_bgcolor">@color/spinner_privacy_popupBackground_dark</item>
        <item name="event_info_bgcolor">@android:color/system_neutral1_800</item>
        <item name="event_info_scrollview_bgcolor">@android:color/system_neutral1_800</item>
        <item name="event_info_organizer_color">@color/event_info_organizer_color_dark</item>
        <item name="event_info_description_color">@color/event_info_description_color_dark</item>
        <item name="event_info_body_color">@color/event_info_body_color_dark</item>
        <item name="event_info_label_color">@color/event_info_label_color_dark</item>
        <item name="create_event_date_color">@color/create_event_date_color_dark</item>
        <item name="calendar_owner_text_color">@color/calendar_owner_text_color_dark</item>
        <item name="calendar_date_banner_bgcolor">@color/calendar_date_banner_background_dark</item>
        <item name="app_bar_color">@android:color/system_accent1_800</item>
        <item name="minus_button">@drawable/ic_menu_remove_field_holo_light_dark</item>
        <item name="ic_menu_email">@drawable/ic_menu_email_holo_dark</item>
        <item name="calendar_future_bg_color">@color/calendar_future_bg_color_dark</item>
        <item name="month_other_bgcolor">@color/month_other_bgcolor_dark</item>
        <item name="settings_calendar_offline">@drawable/ic_sync_off_dark</item>
        <item name="iconAboutAuthors">@android:color/white</item>
        <item name="iconAboutLicense">@android:color/white</item>
        <item name="iconSettingsAbout">@android:color/white</item>
        <item name="iconSettingsGeneral">@android:color/white</item>
        <item name="iconAddCalendar">@android:color/white</item>
        <item name="iconCalendarAccount">@android:color/white</item>
        <item name="calendarSpinnerDisabledTextColor">@color/calendar_item_disabled_dark</item>
    </style>
    <style name="CalendarAppThemeBlackMonet" parent="Theme.AppCompat.NoActionBar">
        <item name="colorPrimary">@android:color/system_accent1_500</item>
        <item name="colorPrimaryDark">@color/bg_black</item>
        <item name="colorAccent">@android:color/system_accent2_400</item>
        <item name="light_dark">@android:color/white</item>
        <item name="android:windowBackground">@color/bg_black</item>
        <item name="actionBarPopupTheme">@style/ThemeOverlay.AppCompat.Dark</item>
        <item name="settings_titleText">?android:attr/textAppearanceLarge</item>
        <item name="month_header_bgcolor">@color/month_bgcolor_black</item>
        <item name="agenda_general_bgcolor">@color/agenda_general_background_color_black</item>
        <item name="agenda_day_item_text_color">@color/agenda_day_item_text_color_black</item>
        <item name="edit_event_bgcolor">@color/edit_event_color_black</item>
        <item name="editEvent_small_color">@color/edit_event_small_black</item>
        <item name="android:itemBackground">@color/bg_black</item>
        <item name="recurrence_picker_bgcolor_up">@color/recurrence_picker_background_up_black</item>
        <item name="recurrence_picker_bgcolor">@color/recurrence_picker_background_black</item>
        <item name="done_text_recurrence">@color/recurrence_done_text_color_black</item>
        <item name="spinner_privacy_presence_bgcolor">@color/spinner_privacy_popupBackground_black</item>
        <item name="event_info_bgcolor">@color/bg_black</item>
        <item name="event_info_scrollview_bgcolor">@color/bg_black</item>
        <item name="event_info_organizer_color">@color/event_info_organizer_color_black</item>
        <item name="event_info_description_color">@color/event_info_description_color_black</item>
        <item name="event_info_body_color">@color/event_info_body_color_black</item>
        <item name="event_info_label_color">@color/event_info_label_color_black</item>
        <item name="create_event_date_color">@color/create_event_date_color_black</item>
        <item name="calendar_owner_text_color">@color/calendar_owner_text_color_black</item>
        <item name="calendar_date_banner_bgcolor">@color/calendar_date_banner_background_black</item>
        <item name="app_bar_color">@color/app_bar_black</item>
        <item name="minus_button">@drawable/ic_menu_remove_field_holo_light_dark</item>
        <item name="ic_menu_email">@drawable/ic_menu_email_holo_dark</item>
        <item name="calendar_future_bg_color">@color/calendar_future_bg_color_black</item>
        <item name="month_other_bgcolor">@color/month_other_bgcolor_black</item>
        <item name="settings_calendar_offline">@drawable/ic_sync_off_dark</item>
        <item name="iconAboutAuthors">@android:color/white</item>
        <item name="iconAboutLicense">@android:color/white</item>
        <item name="iconSettingsAbout">@android:color/white</item>
        <item name="iconSettingsGeneral">@android:color/white</item>
        <item name="iconAddCalendar">@android:color/white</item>
        <item name="iconCalendarAccount">@android:color/white</item>
        <item name="calendarSpinnerDisabledTextColor">@color/calendar_item_disabled_black</item>
    </style>
</resources>