I found the answer here: https://stackoverflow.com/a/30632980/875249
To avoid the link its pretty straightforward:
mNavigationView.setItemIconTintList(null);
This disables all state based tinting, but you can also specify your own list too. It worked great for me!
Here is where you can get the details on creating a color state list, but its pretty simple too:
http://developer.android.com/reference/android/content/res/ColorStateList.html
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:state_checked="true" android:color="@color/primary" />
<item android:state_checked="false" android:color="@android:color/white" />
</selector>