Drives and Controls Magazine

Brown and black are the new red and yellow

01 April, 2004

Brown and black are the new red and yellow

The interiors of distribution boards and junction boxes are about to become less colourful. An amendment to the IEE`s Wiring Regulations (BS 7671: 2001) published on 31 March sets out a new, less vibrant colour scheme for single-phase and three-phase mains cabling. The changes are designed to bring the UK closer in line with colour schemes used elsewhere in Europe.

From now on, any electrical installation work will have to use either the new colours, or the previous colours - but not both. From 31 March, 2006, installers will no longer be allowed to use the old colours, but existing installations will not have to be rewired.

Where alterations or additions are made to an installation so that so that there is a mixture of old and new colours, warning notices will have to displayed at or near the appropriate distribution board


For three-phase installations, the new phase colours are brown, black and grey (top picture, above) - instead of the existing red, yellow and blue (lower picture) - and the neutral colour will be blue instead of black. The protective conductor will still be green and yellow. Alternatively, all three of the phase conductor cores can be coloured brown, and marked as L1, L2 and L3 at the terminations (as shown below).

For single-phase installations, the red phase will be brown, and the black neutral will turn blue. As with three-phase systems, the protective conductor will be green and yellow. The "new" colours have been used in flexible cables for appliances since 1969, and the IEE has been mulling over the latest changes since then. In 1998, it formed a working party to draw up the new colour scheme.

Eleven out of 14 European countries already use combinations of blues and browns for their phase conductors. But adopting similar colour schemes is not likely to lead to savings in cable costs, because most countries use different types of cable. For example, the UK is the only country to favour wire-armoured cables and the flat twin-with-earth cable used in domestic installations.

To publicise the new colour scheme, almost 500,000 information leaflets have been distributed. Copies can also be downloaded from The IEE has also produced updated versions of its Wiring Regulations and On-site Guide.