How to change the color of the menu icon on the MasterPageDetalis xamarin.forms?

Change in your base theme from style.xml

<style name="MyTheme.Base" parent="Theme.AppCompat.Light.NoActionBar">
            <item name="drawerArrowStyle">@style/DrawerArrowStyle</item>
        </style>
        <style name="DrawerArrowStyle" parent="@style/Widget.AppCompat.DrawerArrowToggle">
            <item name="spinBars">true</item>
            <item name="color">@color/green</item>
        </style>

Please suggest me if i'm wrong

In the new version of Forms you would change the ActionBar color (and text color) like this:

var navigon = new NavigationPage(new WebViewPage());
    navigon.BarBackgroundColor = Color.Teal;
    navigon.BarTextColor = Color.White;

If you using MasterDetailPage you use override OnAppearing in your MasterDetailPage it should work.