Old vs New Cable Colours

In 2006 the UK adopted the harmonised European colour code for fixed wiring. If your home was wired before 2006, you'll find the old colours. Both systems are still in active use.

Colour Comparison

Pre-2006 (old)Post-2006 (new)LiveRedBrownNeutralBlackBlueEarthGrn/YelGrn/Yel

Mixing Old and New

When extending an old circuit, you must identify conductors where they connect to new wiring:

  • Old red conductors used as live: sleeve or mark with brown
  • Old black conductors that remain as neutrals: leave as-is (black is already a valid identifier for neutral in the old code)
  • Old black conductors used in a live role (e.g. switch returns): must be sleeved brown at both ends

The following label must be fixed at the consumer unit — use the exact wording required by BS 7671 Regulation 514.14.1:

"Caution — This installation has wiring colours to two versions of BS 7671. Great care should be taken before undertaking extension, alteration or repair that all conductors are correctly identified."

Switch Returns

In both systems, a cable used as a switch return (a neutral core repurposed as live) must be sleeved brown at both ends to indicate it is live when the switch is on.

Important: Black-sleeved or unsleeved return conductors are a common find in old installations. They are potentially dangerous — always check with a non-contact tester before touching any black conductor.