The two tone green bays were quite possibly World Fair ltd edition models.. http://thelatebay.com/index.php?topic=1112.0 If you drop Birdy a quick pm, I am sure he will be able to tell you the colour codes
Is your bus an import? The colour is 73/4 combo only and not many were produced. I was under the impression that they were produced for the western states only. Colours are Ravenna green and Apple green L64M & L65K
Currently in the process (starting) of restoring a 1975 Bay http://vwbaycamper.blogspot.com/2011/12/our-new-1975-vw-t2-camper.html#!/2011/12/our-new-1975-vw-t2-camper.html. My wife saw the picture of the two tone green bus and it has been decided although not the original colour that is the way we are going.
old guy next door had a late 03 bug in apple green from brand new when i was a nipper and it was always mint such a great colour for any 70's vw but it would look ace on a latebay defo do it