I do wish they would leve the bloody colours alone, I was working on an old conduit installation a while ago, the earth was provided by the conduit, and the lighting was wired with red as switchfeeds, blue as switchwires, white for the 2 way strappers and black for the neutral (as expected). So a fitting would have a blue for live and two black for neutrals, I needed to pull some neutrals back and pull a new leg back, with the result that the fitting would have ended up with neutrals as blue/black and line as blue. ended up renewing the switchwire to brown as well as it would have been rather silly otherwise!