Change spinner background color but keep arrow

I did a little modification based on @Mansur Khan ‘s answer.

We don’t have to add an ImageView in this case because the spinner already has a triangle arrow. So check the code below:

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="8dp"
        android:background="#FFFFFF">
        <Spinner
            style="@style/Widget.AppCompat.DropDownItem.Spinner"
            android:layout_width="match_parent"
            android:layout_height="70dp"
            android:id="@+id/sign_up_country"
            />
    </RelativeLayout>

Here is the screenshot

Before:

After: