Uk fixed wiring insulation colours

Beammeupsnotty · 2025-03-15T04:57:52+0000

Why did we change insulation colours from Red,Yellow and blue / black to brown,grey and black?

littlespark · 2025-03-15T07:58:14+0000

European harmonisation was the official title of it.

Back in 2005 to 2007, all new work had to be in the new colours, whether new installation or addition to existing….
The 2 years was to give companies a chance to use up their old stock. But from 2007, it all has to be the new colours.

Red, yellow, blue was much easier to see in a dimly lit work area… and confusion came about with blue and black basically swapping purpose.

Avo Mk8 · 2025-03-15T10:10:35+0000

There's interesting background to cable colours over the years on the IET website, and the story of why we ended up where we did, accelerated by 'harmonisation'.

brianmoooore · 2025-03-15T15:29:59+0000

littlespark said:
Red, yellow, blue was much easier to see in a dimly lit work area… and confusion came about with blue and black basically swapping purpose.

I find it more annoying when creating wiring diagrams. Black and blue have the same abbreviation.
Also possible confusion as to whether Gr/Y is a single green/yellow earth wire, or a grey wire plus a yellow wire.