AppCompat Toolbar: Change Overflow Icon Color in ActionMode

Add the below line into your theme attribute:

<item name="android:textColorSecondary">@android:color/white</item>

This can be achieved by setting the android:textColorSecondary theme attribute.

For example, suppose you have the following toolbar, which uses the theme MyToolbarStyle:

<android.support.v7.widget.Toolbar
  xmlns:app="http://schemas.android.com/apk/res-auto"
  android:id="@+id/main_toolbar"
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:minHeight="?attr/actionBarSize"
  theme="@style/MyToolbarStyle"
/>

Next, define the style MyToolbarStyle, inheriting from ThemeOverlay.AppCompat.ActionBar. Finally, modify the color of the overflow icon by adding an item for android:textColorSecondary:

<style name="MyToolbarStyle" parent="ThemeOverlay.AppCompat.ActionBar">
  <item name="android:textColorSecondary">#333333</item>
</style>