That's a known issue. Unfortunately, it's not possible to make menu permissions less restrictive with the free version of the plugin. You can use it to hide menus from a role, but not to give a role access to menus it couldn't access before.
The reason why it works like that is that most admin pages have at least two capability checks - one in the admin menu and one in the code that generates and displays the page. AME can change the capability associated with the menu, but it's not possible to change the second check without actually editing WordPress/plugin source code.
The Pro version gets around this by automatically detecting what capability a role would need to access a menu and giving the role that capability on-the-fly.
What you could do is use a role management plugin like User Role Editor to give the Editor the capability required to access the Appearance page.