During all the years I had access to Theo's green car, I never noticed that the lower shell of the front seat is green when the back rest is white, see the pictures. On all the other pictures I have the lower shell has the same color as the bolsters.
What do you think? Option, factory error, later swap? Unfortunately, I don't have the trim number of that car which was sold some months ago.

Front seat1.jpg Front seat3.jpg