Colour marking cables.

[winston1]

You're a bit out of date there. They have harmonised too... sort of.

But as I keep saying this forum is ELECTRICS UK

Sort of! Exactly. Red is used for L in fixed wiring.

 

[plugwash]

When it was installed it should probably have been sleeved in accordance with the current colour code at the time, be that red/black/green, red/black/green+yellow or brown/blue/green+yellow but that is water under the bridge, the question is what if-anything should be done about it now.

The electrical safety council's best practice guide says

Non-compliances with the current edition
of BS 7671 that do not give rise to danger
and do not require reporting
<--snip-->
Switch lines not identified as line conductors at
terminations (for example, a conductor having
blue insulation is not sleeved brown in switches
or lighting points)
<--snip-->
Cable core colours complying with
a previous edition of BS 7671.

While it doesn't explicitly cover the case of a single phase cable where some conductors are identified with "old" colours and others with "new" colours or cables identified with pre-bs7671 UK colour codes, I would say it fits into the same spirit.

 

[SUNRAY]

For appliance flexes yes. But for fixed wiring L is red N is blue E is green/ yellow.

The T&E I used In France a lot of years ago (1980's?) was certainly red and blue, please let's not get into the 'France don't use T&E' saga.
However the later product I've seen is definitely the same colours as the flex with insulated earth.
Realistically My impression is their electricians tend to use various colours of singles for their line, brown seems to be the norm but red and black also seem popular with purple, white and orange for SL & strappers (except they like their retractive switches and relay for multiway switching) their 3ph is often all browns or all blacks with blue Neutral. Yellow is also to be seen for earths in places (and I believe the main reason we ended up with green/yellow stripe).

 

[sparkwright]

I've been sent an EICR with a view to doing the work, most of it is things like earthing metal accessories, damage etc.
There has been significant rewiring with harmonised T&E
However there are 5 SWA's in the CU described as requiring colour identification.
One is 2 core red and black, the other 4 (believed to be 16,10 & 6mm²) are red, yellow, blue and the yellow's have green sleeve.

I would say the correct thing to would be to sleeve the blue with black sleeving.

I think it would be wrong to leave the red unsleeved and the blue unsleeved - because you would have a cable with one wire unharmonised colouring and one wire with harmonised colouring.

 

[sparkwright]

I would say sleeving the red with brown sleeving wouldn't be the best solution - bearing in mind when the NON-harmonised cables were used, there was absolutely no need to sleeve them with harmonised colours.

Although there would be technically nothing wrong with sleeving the red with a brown sleeve, it goes against the principle that there is no need to over-sleeve old NON-harmonised cables.