I had the same issue on a C14 Edge, Steve's right it's a protective coating (as far as the C14 Edge is concerned) and could only be seen when the primary was dewed up. It looks very similar to tape, as if there's some been stuck on the primary at some stage.
It doesn't look nice though and just looks poorly applied, whether it affects all units I don't know???
I've enclosed a photo of my C14 Edge which I got replaced at the time as no-one knew what it was (approx. 5 years ago) it also had the blue tinge which doesn't show up on this photo.
EDIT: Just to add the corrector plate or camera had nothing to do with the blue tinge colour on the primary.