Wiring colors in a distribution box indicate the function of each wire: live (hot), neutral, or ground, helping ensure safety and proper electrical connections.

Common Wire Color Meanings

• Live (Hot) Wires: Typically carry current from the power source to devices. In the US, black or red wires are commonly used, while in Europe and IEC-compliant countries, brown or black may be used for single-phase AC, and brown, black, or gray for three-phase AC .
• Neutral Wires: Return current to the power source and complete the circuit. In the US and Canada, neutral wires are usually white or gray; in IEC countries, blue is standard .
• Ground (Protective Earth) Wires: Provide a safety path to prevent electric shock. These are green, green with yellow stripes, or bare copper in most regions .

Regional Standards

• United States (NEC): Green, bare, or green/yellow for ground; white or gray for neutral; any other color for live wires .
• Canada (CEC): Similar to NEC; white for neutral, green or bare for ground, and other colors for live wires .
• Europe and IEC-compliant countries: Brown for live, blue for neutral, green/yellow for ground .

Special Cases

• Three-phase systems: Different colors may be used for each phase to distinguish them, e.g., brown, black, gray in IEC systems or black, red, blue in NEC systems .
• High-leg delta systems (US): The high-voltage phase is often marked with orange .
• DC systems: Positive is usually red, negative black, and grounded conductor or neutral white or gray .

Safety Considerations

• Wire color indicates intended function but does not guarantee safety; always test wires with a multimeter before handling .
• Older installations or renovations may not follow current standards, so labeling and verification are essential .
• Proper identification reduces the risk of electric shock, equipment damage, and wiring errors during maintenance or upgrades . Understanding these color codes allows electricians and homeowners to safely identify and work with electrical circuits, ensuring compliance with local regulations and minimizing hazards.