P
Paul_C
Is it, as per what you've written above - blue for neutral (with black sleeve!) and yellow (with G/Y sleeve) for CPC - or is it yellow for neutral (with black sleeve), maybe because of fears about black/blue confusion?
I don't think I've ever seen red/yellow/blue SWA in such an application used any other way than blue (sleeved black) for N and yellow (sleeved green or green/yellow) for E. It was almost certainly the natural application when yellow replaced white, since blue already had the exemption for neutral under the 13th edition, and soon after green/yellow started to appear as an alternative to green for earth, so the yellow core was seen as being "halfway there" already. And it was the replacement for white, which was also sleeved green for earth under the 13th edition.