In The Netherlands pre 1977, we had Red as Neutral colour, so it was probably the old European colour coding for Neutral.
Red was the old color for earth/ground in Austria, Germany, and a few other places. It seems that all sorts of different systems were in use across Europe, in some cases multiple systems within the same country.
There's a thread in the reference area in which we collected together some postings about this: International color codes
The three blue phases is interesting though. I'm sure Ragnar will correct me if I'm wrong, but for single-phase I understood that the old Austrian system followed the German, i.e. red=ground, black=hot, gray=neutral. So I would have expected at least one phase in a 3-ph system to be black.
The purple sheath is quite unusual as well.
One other point regarding the construction of that connector: Is there any sort of link between the earth pin and the casing when it's all assembled?
[This message has been edited by pauluk (edited 01-26-2007).]