Core Colours

Core Colour Harmonisation
for low voltage fixed wiring cables

Since 31st March 2004 the cable core colour identification for low voltage fixed wiring cables has been aligned across Europe.

The change in UK was effected by the publication of an amendment to BS 7671 (wiring regulations). By comparison with previous practice, the new core colour identification has blue to identify neutral, instead of of black, with phase colours now being brown, black and grey.  The combination green-and-yellow continues to be used to identify protective earth conductor.

A supporting article was published by IEE (now IET) in “Wiring matters of Spring 2004”. This may be accessed via:

http://www2.theiet.org/Publish/WireRegs/WiringMatters/index.cfm