Vitra Eames Lounge Chair with white shells ?  

Hi there. I have the chance to buy a Vitra Eames Lounge Chair.
The seller bought it in the 80s from a shop which just sold original classics from Knoll, Vitra and so on.
It doesn´t look like a knockoff from the pics. European base and so on.
The shells are white (with brown leather).
I know black ones, rosewood and so on..., but white shells?
Does anyone knows them, or is it maybe new lacquered by the shop itself just for this owner than?
The seller (1.owner) told me, he had bought it in that white.
I called vitra, but the man on phone didn´t knew exactly what was offered in the 80s as a special edition maybe. So I hope someone can help me here. It is a bit far away from me, to have a personal look...