They weren't only an option on Dragon green mk3's, mine came from a lightish metallic blue GL, very similar to the OP's car. It had only done 30k miles, so the seats are in great condition!
As mentioned, the bolsters on the back section are ever so slightly smaller than my old GTI seats, but the bolsters on the seat section actually seem a little bigger, certainly more huggable/holdable.
They are indeed grey, but a very light shade of.