February 25, 2025

Electrical wiring is the backbone of any residential, commercial, or industrial infrastructure. Understanding the correct wiring colours is crucial for ensuring safety, proper functionality, and compliance with legal regulations. Electrical wiring colour codes are established to standardize installations, prevent hazards, and make troubleshooting easier.

In India, the Bureau of Indian Standards (BIS) has set specific guidelines for electrical wire colour coding under IS 732 and IS 3043. These codes help distinguish between live, neutral, and earth wires, which is essential for electricians, engineers, and even homeowners. A proper understanding of these wiring colours can prevent serious issues such as electric shocks, fires, and system failures.

This comprehensive guide will cover the standard wire colour codes in India, their significance, best practices, and why adherence to these standards is essential for safe electrical installations.

Standard Wire Colour Codes in India

India follows the IS 732:2019 standard for electrical wiring colours, which aligns with international IEC (International Electrotechnical Commission) standards. Electrical wires are colour-coded to help electricians and engineers identify the function of each wire within a circuit. The commonly used colours include:

Live (Phase) Wire: Red – Carries current from the power source to the load.

Neutral Wire: Black – Completes the circuit by returning current to the power source.

Earth (Ground) Wire: Green or Green with Yellow Stripe – Provides a safe path to dissipate excess current into the ground, preventing electric shocks.

These colour codes are essential for single-phase electrical systems commonly used in homes and offices.

Three-Phase Wiring Colour Codes

For larger buildings, industries, and commercial setups, three-phase electrical systems are widely used. The wire colours for these systems are:

Phase 1 (L1): Red

Phase 2 (L2): Yellow

Phase 3 (L3): Blue

Neutral (N): Black

Earth (Ground): Green or Green with Yellow Stripe

Following these colour codes ensures that each phase is correctly identified and balanced for efficient power distribution.

Wiring Colour Codes in Different Applications

1. Domestic Wiring (Single-Phase Systems

Live Wire – Red
Neutral Wire – Black
Earth Wire – Green, Green-Yellow

2. Industrial Wiring (Three-Phase Systems)

Phase Wire (L1) – Red
Phase Wire (L2) – Yellow
Phase Wire (L3) – Blue
Neutral Wire – Black
Earth Wire – Green, Green-Yellow

Additional Electrical Wiring Colours Used in India

1. Black (Older Neutral and Sometimes Phase in Multi-Wire Circuits)
In wiring systems, black was commonly used as the neutral wire.
In some multi-wire circuits, black may be used as a phase wire in three-phase systems.
Precaution: If working with older systems, verify with a tester before assuming it is a neutral wire.

2. Yellow (Alternate Phase Wire in Three-Phase Systems)
Used as one of the three-phase wires (L2) in industrial three-phase wiring.
Sometimes, it is found in single-phase systems where a yellow wire might indicate a phase conductor.
Precaution: Always check if the yellow wire is live before handling.

3. Grey (Rarely Used in Domestic Wiring, Common in Control Circuits)
Found in industrial control panels and switchgear.
Used in some electrical installations as an additional phase wire (L3) in three-phase systems.
Precaution: Ensure that grey is not mistaken for neutral or earth, as it can carry current.

4. White (Control Wires in Switchboards & Lighting Circuits)
Occasionally used in control wiring for switches and lighting circuits.
In some electrical systems, white wires serve as neutral wires, though this is uncommon in India.
Precaution: Confirm its role in the circuit before making connections.

5. Purple (Control Wiring & Specialized Applications)
Sometimes used in control circuits in commercial and industrial installations.
May also appear in specialized systems such as fire alarm circuits.
Precaution: Verify voltage and function before handling.

6. Orange (Interconnection Wire in Three-Phase Systems & UPS Wiring)
Sometimes used as an intermediate wire in three-phase installations.
In UPS (Uninterruptible Power Supply) systems, orange wires may indicate an isolated phase.
Precaution: Be cautious as orange wires may still carry voltage even when the main power is off.

7. Pink (Control and Signal Wiring)
Used in control circuits for automation systems.
Found in communication wiring in industrial setups.
Precaution: Pink wires do not usually carry high voltage but should still be checked.

8. Violet (Special Circuits & Auxiliary Power Supply)
Found in some auxiliary power systems in industries.
May be used in low-voltage DC circuits.
Precaution: As it is less common, always check the circuit diagram before working.

If you would like to learn more about the current Indian electrical wiring standards and IS Regulations, you can visit our electrical wiring regulations guide in India.

Importance of Adhering to Wiring Colour Codes

Electrical wiring colour codes are not just for organization; they play a crucial role in safety and efficiency. The key reasons to follow standard wiring colours include:

Prevention of Electrical Hazards: Proper identification of wires reduces the risk of electric shocks, short circuits, and fires.

Ease of Maintenance & Troubleshooting: Standardized colours make it easier for electricians to diagnose issues and make repairs quickly.

Regulatory Compliance: Adhering to BIS standards ensures installations are legally compliant, preventing penalties and potential insurance claims.

Enhanced System Efficiency: Correct wiring ensures optimal performance and prevents unnecessary system failures.

Best Practices for Safe Electrical Wiring

To maintain safety and efficiency in electrical installations, consider the following best practices:

1. Use High-Quality Wires – Always use BIS-approved electrical wires to ensure durability and safety.
2. Hire Certified Electricians – Electrical work should be done by qualified professionals who understand the latest wiring standards.
3. Conduct Regular Inspections – Periodic checks help detect damaged or aged wires before they become hazardous.
4. Label Wires Clearly – Proper labelling helps with maintenance and reduces the chances of errors.
5. Follow Local Regulations – Ensure compliance with national and regional electrical codes to avoid legal issues.

Conclusion

Understanding and following the standardized electrical wiring colour codes in India is crucial for the safety, efficiency, and reliability of electrical systems. Whether it’s a small home installation or a large industrial setup, using the right wire colours helps prevent accidents, simplifies troubleshooting, and ensures compliance with regulations. By adhering to these guidelines and best practices, homeowners, electricians, and businesses can contribute to safer and more efficient electrical installations across the country.

Investing time in understanding electrical wire colors and their functions can save lives, prevent costly damages, and enhance the overall efficiency of electrical systems. Always prioritize safety, and when in doubt, consult a licensed electrician to ensure your wiring follows the correct standards.