How can change bg color of dropdown?

[alexei-28]

In layout:

 <com.rengwuxian.materialedittext.MaterialAutoCompleteTextView
                android:id="@+id/recipient_edit_text"
                style="@style/EditText.OneLine"
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:layout_marginTop="@dimen/standard_padding"
                android:completionThreshold="0"
                android:hint="@string/recipient_label"
                android:inputType="phone"
                android:paddingEnd="42dp"
                android:paddingRight="42dp"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintStart_toStartOf="parent"
                app:met_floatingLabelAlwaysShown="true"
                app:met_floatingLabelText="@string/tx_recipient" /

and here reult:

I need to change bg color (black) of dropdown to white color.