Electrical Wire Colors Meaning

The primary power wire in standard North American household circuits. It carries electricity directly from the breaker panel to outlets and switches. Never touch without turning off the main breaker!

Completes the electrical circuit by returning electricity back to the service panel. Even though it is grounded at the panel, a loose neutral under load can deliver a serious electric shock.

A life-saving safety mechanism. It directs stray electrical fault currents safely into the physical ground (earth rod) to immediately trip the circuit breaker instead of electrocuting someone touching a metal appliance.

Secondary hot conductor. In 240V circuits (dryers, ovens, water heaters), red provides the opposite 120V phase leg. In 120V circuits, it serves as a traveler wire for 3-way stairway switches or interconnected smoke alarms.

Used as traveler wires pulled through metal conduit pipes in commercial or complex residential switch loops.

The standard Live (phase) wire across all modern UK and European Union installations (harmonized since 2004). Replaced the old UK red wire.

CRITICAL WARNING: In Europe and the UK, Blue is the NEUTRAL return wire (replaced the old black neutral). In the US, blue is HOT! Never assume blue is harmless without checking geography.

International earth safety wire with dual green and yellow diagonal stripes for colorblind visibility. Connects to metal casings to divert electrical faults.

Direct current positive battery lead. In cars, solar panels, and electronics power supplies, red connects to the positive terminal (+).

FATAL CONFUSION ALERT: In DC circuits, Black is NEGATIVE (Ground)! In US AC household wiring, Black is 120V HOT! Never mix up AC and DC color codes.