You can’t change it from OptionsMenu. Instead, you can try programmatically using below code:

Kotlin with AndroidX:

 val searchView: SearchView = item.getActionView();
    val editText = searchView.findViewById<EditText>(androidx.appcompat.R.id.search_src_text)
    editText.setTextColor(getResources().getColor(R.color.white));
    editText.setHintTextColor(getResources().getColor(R.color.white));

Java with AndroidX:

SearchView searchView = (SearchView) item.getActionView();
    EditText editText = (EditText) searchView.findViewById(androidx.appcompat.R.id.search_src_text);
    editText.setTextColor(getResources().getColor(R.color.white));
    editText.setHintTextColor(getResources().getColor(R.color.white));

In the parent theme add the following:

1. In the parent theme add the following:

<item name="android:editTextColor">@android:color/darker_gray</item>

Note that you can replace “@android:color/darker_gray” with your desired color.

For changing the hint you can use this:

android:queryHint="my_hint_here"

follow this link for more details

Below code worked for me:

  @Override
    public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
        super.onCreateOptionsMenu(menu,inflater);
        MenuItem item = menu.findItem(R.id.action_search);
        SearchView searchView = (SearchView) item.getActionView();
        EditText editText = (EditText) searchView.findViewById(androidx.appcompat.R.id.search_src_text);
        editText.setTextColor(Color.WHITE);
        item.setShowAsAction(MenuItem.SHOW_AS_ACTION_COLLAPSE_ACTION_VIEW | MenuItem.SHOW_AS_ACTION_IF_ROOM);
        item.setActionView(searchView);
        searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
            @Override
            public boolean onQueryTextSubmit(String query) {
                return false;
            }
            @Override
            public boolean onQueryTextChange(String newText) {
                return false;
            }
        });
        searchView.setOnClickListener(new View.OnClickListener() {
                                          @Override
                                          public void onClick(View v) {

                                          }
                                      }
        );

    }

Add a custom theme to your Toolbar.

Something like this

<androidx.appcompat.widget.Toolbar
        android_id="@+id/toolbarMenu"
        android_layout_width="match_parent"
        android_layout_height="wrap_content"
        android_theme="?ref_toolbar_icon_tint"
        app_popupTheme="?ref_toolbar_popup_menu">

Then in your styles.xml add the following

<style name="toolbar_icons_theme_dark" parent="Theme.AppCompat.Light.NoActionBar">
    <item name="colorControlNormal">--color of the icons--</item>
    <item name="android:editTextColor">--text color--</item>
    <item name="android:textColorHint">--hint color--</item>
</style>

and just call this custom style into your parent theme

    <item name="ref_toolbar_icon_tint">@style/toolbar_icons_theme_dark</item>

I implemented a search view in options menu by using the following menu code.

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns_android="http://schemas.android.com/apk/res/android"
    xmlns_app="http://schemas.android.com/apk/res-auto">
    <item
        android_id="@+id/search_toolBar"
        android_title="Search"
        android_icon="@drawable/search_icon"
        app_showAsAction="always|collapseActionView"
        app_actionViewClass="androidx.appcompat.widget.SearchView"
        />
</menu>

How to change the color of text of my search view. I want to also change the hint of searchview.