Can you explain more about the Kea/Loa trends? Kilauea is active (like Mauna Loa), so presumably you are not referring to the temporal evolution of silica content.

As a native Northeasterner, I submit that not all color-changing leaves are equally brilliant. The best fall colors come in places where you have a dense mixture of red maples + sugar maples, i.e. Vermont and the Michigan upper peninsula.