So to try and sum up the current position we have the following evidence....
1) TIE lenses are grey and were made at the same time.
2) The Ribbed neck Stormtroopers made after ANH by AA with "Hero" eye lenses were also grey
3) Inconclusive screen caps. No sign of green, just "dull" grey/black
4) The guy who made them said they were grey
5) A guy who wore one said they were green. However the 50 Stunts certainly were green so maybe theres some confusion?
Art Department - There's no evidence that the "Art Department" did any vac forming. None whatsoever. IMO you cant say "the Art Department did x, y and z" without any evidence to back this up.
Therefore my position has always been that without the lack of anything specifically indicating green, I go with the colour we KNOW lenses were originally made for and thats Grey.
Perhaps the most damning thing for the "green case" is what defstartrooper just said - Why change the colour of the lenses from grey to green if you don't want the audience to see that new colour?
However I'm still open to ideas
Cheers
Jez