Still referred to as gold and appeared as such on the screen. I understand that the material had a different look but it came across as gold, or green/gold.
Plus it's possible that they chose the green material especially because it would end up looking gold when it was lit by the studio lights and filmed.
From what I understand that happens quite a lot in filming. Costumes sometimes have to be made in a different colour so that they appear to have the "right"(intended) colour on-screen.