Sorry, I don't understand. 
Hi,
I think playmo1989 means he's seen other steck roof pieces with the same odd purple colour (correct me if I'm wrong!).
My guess is that the piece(s) is (are) somewhat discoloured in the sun, but I suspect the strange colour might also be due, in part, to poor lighting and dubious colour capture in the vendor's camera. I've seen digital cameras do some
very bizarre things with colours when the pictures are taken using poor artificial lighting.
So, clearly genuine Playmobil, but the colour seen in picture is probably not the colour the piece was originally, or even the
real colour it is now.
Cheers,
AndrewL