White ToolbarItem icons showing black - xamarin.forms

Question

I have a Xamarin Forms TabbedPage which contains a NavigationPage and I'm setting a ToolbarItem with two white icons. For some reason they appear black when my icons are white:
Here is my Xaml code:
<TabbedPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:views="clr-namespace:Pick.Views"
x:Class="Pick.Views.MainView"
xmlns:utility="clr-namespace:Pick.Utility"
utility:ViewModelLocator.AutoWireViewModel="False">
<NavigationPage Title="{Binding Strings[Menu_MyPools]}">
<x:Arguments>
<views:PoolsView BindingContext="{Binding PoolsViewModel}"/>
</x:Arguments>
<NavigationPage.ToolbarItems>
<ToolbarItem Command="{Binding CreatePoolCommand}" Order="Primary" IconImageSource="ic_add_white_36dp.png">
</ToolbarItem>
<ToolbarItem Command="{Binding JoinPoolCommand}" Order="Primary" IconImageSource="ic_login_white_36dp.png">
</ToolbarItem>
</NavigationPage.ToolbarItems>
</NavigationPage>
I have tried setting AppThemeBinding and changing Styles.xml but nothing seems to work:
<ToolbarItem Command="{Binding CreatePoolCommand}" Order="Primary">
<ToolbarItem.IconImageSource>
<OnPlatform x:TypeArguments="ImageSource">
<On Platform="Android" Value="{AppThemeBinding Light=ic_add_white_36dp,Dark=ic_add_white_36dp}"/>
<On Platform="iOS" Value="{AppThemeBinding Light=ic_add_white_36pt,Dark=ic_add_white_36dp}"/>
</OnPlatform>
</ToolbarItem.IconImageSource>
</ToolbarItem>
Any ideas?
Here my styles.xml:
<resources>
<style name="MainTheme" parent="MainTheme.Base">
</style>
<!-- Base theme applied no matter what API -->
<style name="MainTheme.Base" parent="Theme.AppCompat.Light.DarkActionBar">
<!--If you are using revision 22.1 please use just windowNoTitle. Without android:-->
<item name="windowNoTitle">true</item>
<!--We will be using the toolbar so no need to show ActionBar-->
<item name="windowActionBar">false</item>
<!-- Set theme colors from http://www.google.com/design/spec/style/color.html#color-color-palette -->
<!-- colorPrimary is used for the default action bar background -->
<item name="colorPrimary">#188223</item>
<!-- colorPrimaryDark is used for the status bar -->
<item name="colorPrimaryDark">#1976D2</item>
<!-- colorAccent is used as the default value for colorControlActivated
which is used to tint widgets -->
<item name="colorAccent">#FF4081</item>
<!-- You can also set colorControlNormal, colorControlActivated
colorControlHighlight and colorSwitchThumbNormal. -->
<item name="windowActionModeOverlay">true</item>
<item name="android:datePickerDialogTheme">#style/AppCompatDialogStyle</item>
</style>
<style name="AppCompatDialogStyle" parent="Theme.AppCompat.Light.Dialog">
<item name="colorAccent">#FF4081</item>
</style>
</resources>
Tabbar.axml:
<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.TabLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/sliding_tabs"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="?attr/colorPrimary"
android:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar"
app:tabIndicatorColor="#android:color/white"
app:tabGravity="fill"
app:tabMode="fixed" />
Toolbar.axml:
<android.support.v7.widget.Toolbar
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="?attr/colorPrimary"
android:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar"
android:popupTheme="#style/ThemeOverlay.AppCompat.Light" />

Answer 1

I just figured out my issue. Turns out that I had XML files corresponding to my images which had a vector definition inside. Not sure if those were automatically created by one of my material design icons VS extension. Once I remove, I see my icons in the right color.