In article ,
Terry Casey writes

Finally, the sleeving was changed from green to green/yellow ..

IIRC, it was to make it easier for colour-blind people to identify.

There's also been another change: the cores in T&E (=romex) used to be
red and black for phase and neutral, now it's been harmonised with
Europe to brown and blue.

Three-phase wiring has been harmonised from red, blue and yellow for the
phases and black neutral to brown, black, black and blue neutral. Yeah,
I know...

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