In a typical US home electrical distribution box, neutral wires are white or gray, ground wires are green or bare, and hot wires are usually black, red, or blue.

Wire Color Overview in the US (NEC Standards)

• Neutral (Grounded Conductor): White or gray insulation; carries current back to the panel and completes the circuit safely .
• Ground (Equipment Grounding Conductor): Bare copper, green, or green with yellow stripe; provides a safety path to prevent electric shock .
• Hot (Ungrounded Conductor): Commonly black for Line 1, red for Line 2, and blue for Line 3 in three-phase systems; other colors may be used but must be distinguishable from neutral and ground .

Typical Single-Phase Residential Wiring

• 120V circuits: Black or red for hot, white for neutral, green or bare for ground .
• 240V circuits: Two hot wires (black and red), white neutral if needed, green or bare ground .

Three-Phase Wiring (Commercial or High-Power Residential)

• Line 1: Black
• Line 2: Red
• Line 3: Blue
• Neutral: White or gray
• Ground: Green or bare .

Safety and Regional Notes

• Older homes may have non-standard or faded wire colors; always verify with a tester before touching wires .
• Canadian wiring is similar to the US, with white for neutral and green or bare for ground .
• European/UK wiring (IEC standards): Brown for live, blue for neutral, green/yellow for ground .
• Labeling: When mixing old and new wiring, label wires to avoid confusion .

Practical Tips

• Always turn off power at the breaker before working on any circuit.
• Use a voltage tester to confirm which wires are live.
• Follow local electrical codes for installation and repairs. Understanding these color codes ensures safe identification of wires in your home electrical distribution box, simplifies maintenance, and prevents hazardous mistakes.