Distribution box wiring colors typically follow regional standards: green/yellow for ground, white/gray for neutral, and various colors for live wires depending on phase and region.

Standard Wiring Colors

1. Protective Ground (Earth):

• Green, Green/Yellow stripe, or Bare copper is used universally for grounding to ensure safety and prevent electric shock (NEC, IEC, CEC) . 2. Neutral Wire:
• White or Gray in the US and Canada (NEC/CEC)
• Blue in IEC-compliant countries (Europe, UK, and others) . 3. Live (Line/Phase) Wires:
• Single-phase AC (120V–240V):
  • US: Black or Red for hot wires
  • IEC: Brown for L1, Black for L2 (older systems may vary)
• Three-phase AC:
  • US: Black, Red, Blue for L1, L2, L3
  • IEC: Brown (L1), Black (L2), Gray (L3)
• High-leg or split-phase systems may have additional color coding, such as orange for the high leg in 208V systems . 4. DC Circuits:
• Positive (+): Red
• Negative (−): Blue or Black
• Ground: Green or Green/Yellow .

Key Considerations

• Regional Variations: Always verify local codes, as colors may differ slightly between countries or older installations .
• Old vs. New Wiring: Older systems may use outdated colors; labeling is recommended when mixing old and new wires .
• Safety First: Never assume a wire's function based solely on color; always test before handling .
• Documentation: Distribution boxes should have clear labeling for each terminal and wire to prevent miswiring and simplify maintenance . By following these color standards, electricians and technicians can safely identify and work with live, neutral, and ground wires in distribution boxes, ensuring compliance with local regulations and reducing the risk of electrical hazards.