Home›Learn›Wire Colour Code

REFERENCE · JULY 2026

Wire Colour Code in India — IS 732:2019, NBC 2016 & IEC 60446

Lede (Answer-First)

In India, the wire colour code defined by IS 732:2019 (the Code of Practice for Electrical Wiring Installations issued by the Bureau of Indian Standards) is L1 phase = Red, L2 phase = Yellow, L3 phase = Blue, Neutral = Black, and Earth = Green or Green-and-Yellow stripe. Where installations follow the IEC 60446 harmonised scheme (now consolidated into IEC 60445:2017), the phases are Brown, Black and Grey, Neutral is light Blue and Earth/Protective conductor is Green-Yellow — a pattern increasingly seen on imported equipment, IS 17048:2018 HFFR cables and modern IEC-certified switchgear sold in India. Both schemes are recognised under the NBC 2016 Part 8 §1.4 wiring identification rules, and verification of any cited Indian Standard can be done through the BIS standards portal at bis.gov.in.

Indian Standard Colour Code (IS 732:2019)

The single source of truth for wiring colours in Indian buildings is IS 732:2019, reinforced by NBC 2016 Part 8 (Building Services) §1.4 which mandates that conductor identification at every accessible point — terminations, junction boxes, looping connections — use the standardised colours below. The standard exists for one reason: an electrician opening a junction box ten years from now must be able to identify phase, neutral and earth on sight, without a multimeter, in poor light. Mismatched colour discipline is one of the most cited contributors to electrocution and equipment damage during maintenance.

Conductor	Colour	Notes
L1 phase	Red	First phase of a 3-phase 4-wire system; sole live conductor in a single-phase domestic circuit.
L2 phase	Yellow	Second phase. Phase rotation R-Y-B is conventional for clockwise motor rotation.
L3 phase	Blue	Third phase. Note: in IEC harmonised systems Blue is reserved for Neutral — do NOT confuse the two.
Neutral	Black	Mandatory across single-phase and three-phase 4-wire systems. Sized per IS 732:2019 §3.4 (equal to phase up to 25 sqmm).
Earth (PE)	Green or Green-and-Yellow stripe	Either is acceptable under IS 732:2019; bare copper earth conductors must be sleeved green at terminations.

NBC 2016 Part 8 §1.4 explicitly cross-references IS 732:2019 for these colours and additionally requires that earth-bonding conductors (equipotential bonds to metal water pipes, structural steel, lift shafts) carry the same Green or Green-Yellow identification at every junction. The BIS catalogue entry and the controlled PDF for IS 732:2019 are available via bis.gov.in/standards.

IEC 60446 Harmonised Colour Code (International)

IEC 60446 was the international standard for conductor identification by colour or alphanumeric reference, published by the International Electrotechnical Commission. The 4th edition (IEC 60446:2007) was withdrawn in 2010 and merged into IEC 60445:2017 (Basic and safety principles for man-machine interface, marking and identification — Identification of equipment terminals, conductor terminations and conductors). Engineers and manufacturers continue to refer to the colour scheme as "IEC 60446" because it is the name written on a generation of cable drums and panel drawings.

Conductor	IEC harmonised colour	Notes
L1	Brown	First phase under IEC.
L2	Black	Second phase — note this is Neutral in IS 732:2019, hence the cross-standard hazard.
L3	Grey	Third phase. Replaces older European Black/Brown/Black scheme.
Neutral	Light Blue	Reserved colour — must not be used for any phase conductor anywhere on the circuit.
PE / Earth	Green-and-Yellow stripe	Bicolour combination; pure green or pure yellow alone is no longer permitted.

An Indian electrician encounters IEC 60446 colours in three common situations: (1) imported industrial machinery and CNC equipment whose internal control wiring is loomed Brown/Black/Grey/Blue; (2) IS 17048:2018 compliant HFFR (Halogen-Free Flame Retardant) and certain FR-LSH (Flame Retardant Low Smoke Halogen) cable ranges that ship in IEC colours for export-and-domestic harmonisation; and (3) IEC-certified MCCB and ACB panels manufactured in India for global OEMs. Where IEC and IS 732:2019 colours coexist on the same site, NBC 2016 Part 8 §1.4 requires unambiguous labelling at the boundary — typically a phenolic tag at the panel inlet stating the colour convention used downstream. Reference: iec.ch/publications/IEC60445.

Single-Phase Domestic Wiring

A typical Indian household runs on a single-phase 230 V supply. Inside the wall, three conductors leave the meter: Live = Red, Neutral = Black, Earth = Green or Green-Yellow. This three-wire pattern is what every standard 2.5 sqmm and 4 sqmm house wiring cable from the major Indian manufacturers ships pre-coloured to.

A 2-pin plug (older, ungrounded) carries only Red and Black. A 3-pin plug adds Earth on the larger top pin — Green or Green-Yellow — and is mandatory under IS 1293:2019 for any appliance with an exposed conductive enclosure (geyser, microwave, washing machine, desktop PC). Where you see a double-coloured core in a domestic flexible cable — say a Red-with-White stripe in a multi-core flex — the second colour is a manufacturer trace identifier, not a separate phase; the conductor is still treated electrically as the colour of the dominant body.

Three-Phase Commercial / Industrial Wiring

A three-phase 4-wire 415 V system — used in shops, industrial workshops, lifts and HVAC plant — carries L1 Red + L2 Yellow + L3 Blue + Neutral Black + Earth Green/Green-Yellow under IS 732:2019. Phase rotation is conventionally R-Y-B clockwise; reversing two phases reverses the direction of any three-phase induction motor on the circuit, which is why phase identification at every termination is non-negotiable.

For neutral sizing, IS 732:2019 §3.4 is the authority: for phase conductors up to and including 25 sqmm copper, the neutral is sized equal to phase. Above 25 sqmm, the neutral may be reduced to half-section provided harmonic content is below the limits in §3.4 — a common reason large data-centre and LED-lighting installations specify a full-section neutral despite the size.

Why Wire Colour Matters

Wiring colour discipline is a safety control, not a cosmetic preference. Three failure modes drive it:

Electrocution risk during maintenance. An electrician who assumes Black is neutral (per IS 732:2019) and grabs a Black IEC L2 phase conductor live at 230 V is exposed to a fatal shock. Every cross-standard junction is a hazard.
Equipment damage from reversed phase rotation. R-Y-B reversed becomes R-B-Y, motor spins backwards, pumps run dry, compressors fail seals.
Code violation under NBC 2016. Building handover certification, fire NOC and electrical safety inspection under the relevant State Electrical Inspectorate all require IS 732:2019 colour conformance. Non-conformance means non-occupancy.

NBC 2016 Part 8 §1.4 enforcement is performed by the State Electrical Inspectorate and, for high-rise and industrial occupancies, by the Chief Electrical Inspector to Government (CEIG). BIS licence holders manufacturing cable to IS 694:2010 must mark conductor colour conformance on the drum label, traceable via the CM/L XXXXXXXX ten-digit licence number.

Common Variant Cables

Not every cable on site is a vanilla three-core house wire. Five frequent variants and how their colour code reads:

3-core flat submersible (used for borewell pumps). Conductors are Red + Yellow + Black with a separate Green earth strip — three-phase pump motor, neutral not required.
4-core armoured power cable (LT distribution). Inner cores are Red + Yellow + Blue + Black under XLPE insulation, with the steel armour itself acting as the earth return (per IS 7098-1:1988). Where a separate earth conductor is run alongside, it is Green or Green-Yellow.
Telephone cable (4-pair, 6-pair, 25-pair). Follows the international TIA-598 colour-pair code: Pair 1 White-Blue / Blue, Pair 2 White-Orange / Orange, Pair 3 White-Green / Green, Pair 4 White-Brown / Brown, and so on. Not interchangeable with mains colour code.
Solar DC cable. Red = positive (+), Black = negative (−). Earthing of the module frame is separate, Green-Yellow per IS 732:2019. Because the polarity convention here clashes with mains "Red = phase", solar installers must label DC home-runs at every junction box.
LAN / Cat6 (T568A vs T568B). Eight conductors paired White-Green / Green / White-Orange / Blue / White-Blue / Orange / White-Brown / Brown. T568B swaps the green and orange pairs relative to T568A. Both terminations are functionally equivalent; the rule is end-to-end consistency.

Fire Alarm and Emergency Cable Colour

Fire alarm and emergency-circuit cables in India are typically specified under NBC 2016 Part 4 (Fire and Life Safety) read with IS 1554-1:1988 and the relevant IS 6121 series for wires for telecommunication/signalling. The body colour convention used for fire alarm loop cabling is red outer sheath (so the cable is unmistakable in a service shaft against grey power cable), with cores typically Red + Black for a 2-core loop, or Red + Black + bare drain for shielded variants. Note that Reaction to Fire classification (the cable's contribution to flame spread, smoke and toxicity, e.g. FR, FR-LSH, HFFR) is a separate property from Fire Survival classification (the cable's ability to maintain circuit integrity during a fire, typically tested to BS 6387 CWZ or IEC 60331). A red-sheathed fire alarm cable is not automatically fire-survival rated; the licence holder must specify which.

Frequently asked questions

What is the wire colour code in India?

Under IS 732:2019 and NBC 2016 Part 8 §1.4, the Indian wire colour code is L1 = Red, L2 = Yellow, L3 = Blue, Neutral = Black, and Earth = Green or Green-and-Yellow. This applies uniformly to single-phase domestic, three-phase commercial and industrial 4-wire installations. Imported or IEC-certified equipment may instead use the IEC 60446 harmonised scheme (Brown/Black/Grey/Blue/Green-Yellow), and where the two coexist NBC 2016 §1.4 requires the colour convention to be labelled at the panel boundary.

What is the colour for neutral wire?

The neutral wire colour in India is Black, as specified in IS 732:2019 and reinforced by NBC 2016 Part 8 §1.4. In the IEC 60446 harmonised system used internationally and on imported equipment, the neutral is light Blue — which is a critical distinction because Blue is an L3 phase colour under the Indian standard. Neutral conductor sizing is governed by IS 732:2019 §3.4 (equal to phase up to 25 sqmm copper).

What colour is the earth/ground wire in India?

Earth (protective conductor, PE) in India is Green or Green-and-Yellow striped, per IS 732:2019. Both are equally acceptable; the bicolour Green-Yellow is preferred on cable-cores ≥ 6 sqmm because it cannot be confused with green-pigmented PVC under faded-light conditions. Bare copper earth conductors must be sleeved green at every termination per NBC 2016 Part 8 §1.4.

What colour is the live wire in Indian household wiring?

The live (phase) conductor in a single-phase Indian household is Red, per IS 732:2019. In a 3-pin plug it terminates on the pin marked "L". A red conductor must be assumed live at all times until proven dead with a tested voltage indicator — colour identification is not a substitute for isolation and lock-out under IS 5216 safety practice.

What is the colour code for 3-phase wiring?

A 3-phase 4-wire installation under IS 732:2019 uses Red (L1) + Yellow (L2) + Blue (L3) + Black (Neutral) + Green or Green-Yellow (Earth). Phase rotation is conventionally R-Y-B clockwise. If the installation follows the IEC 60446 / IEC 60445:2017 harmonised scheme, the phases are Brown/Black/Grey with light Blue neutral.

What is the colour code for fire alarm cable?

Fire alarm and emergency loop cables in India typically have a red outer sheath for unmistakable identification in service shafts, with cores Red + Black for a 2-core loop. The cable is specified under NBC 2016 Part 4 read with the IS 1554 / IS 6121 series. Note: a red sheath denotes intent of use, not Fire Survival rating — circuit integrity in fire requires explicit BS 6387 CWZ or IEC 60331 classification on the cable's BIS-traceable test certificate.

Why is the IEC 60446 wiring colour different from Indian standard?

IEC 60446 (now merged into IEC 60445:2017) was harmonised in 2006 across European member states to remove the prior Red/Yellow/Blue scheme, which clashed with colour-blindness accessibility and with the use of Red for DC-positive in solar/control systems. India retained Red/Yellow/Blue under IS 732:2019 because the existing installed base is enormous and the cost of relabelling is prohibitive. NBC 2016 §1.4 recognises both schemes provided the convention is labelled at the boundary.

What colour is the neutral in three-phase IEC harmonised system?

In an IEC 60446 / IEC 60445:2017 harmonised three-phase system the neutral is light Blue. This is *not* the same Blue used as L3 phase under IS 732:2019 — confusing the two on a mixed site is a documented cause of phase-to-neutral short-circuit incidents. Always verify the colour convention written at the panel inlet before working on imported IEC-coloured circuitry.

What is the colour code for solar DC cable?

Solar PV DC cabling in India follows Red = positive (+) and Black = negative (−) as the de-facto convention used by all major module and inverter OEMs. The module-frame earthing conductor remains Green or Green-Yellow per IS 732:2019. Because Red here means DC-positive and not AC-phase, every solar string and combiner-box termination must carry a polarity label to prevent mis-association with mains wiring.

What is the difference between Indian and IEC wire colour codes?

Indian (IS 732:2019): Red/Yellow/Blue phases, Black neutral, Green or Green-Yellow earth. IEC (60446 / 60445:2017): Brown/Black/Grey phases, light Blue neutral, Green-Yellow earth. The two clash dangerously on Black (IS = neutral, IEC = L2 phase) and Blue (IS = L3 phase, IEC = neutral). NBC 2016 Part 8 §1.4 requires explicit labelling wherever both conventions appear on a site.

What is the colour for armoured cable cores in India?

Indian LT armoured cable manufactured to IS 7098-1:1988 carries inner cores in Red + Yellow + Blue + Black for a 4-core variant, with the steel wire armour acting as the earth return. Where a separate earth conductor is provided alongside, it is Green or Green-Yellow per IS 732:2019. The cable's outer PVC sheath is conventionally black; the outer colour is not part of the conductor identification.

Is house wiring colour code the same across India?

Yes. IS 732:2019 is a national standard issued by BIS under the Bureau of Indian Standards Act, 2016, applicable in every State and Union Territory. NBC 2016 Part 8 §1.4 enforces it through the State Electrical Inspectorates. Regional electrician practice may add secondary conventions (e.g. some Tamil Nadu electricians use a striped neutral on 3-phase risers) but the IS 732:2019 colours are the legally enforceable baseline everywhere from Srinagar to Kanyakumari.

METHODOLOGY

Updated weekly by the cablepriceindia.com price-research desk. Last verified: 1 July 2026. Sources cited inline. We are an independent price-discovery service. Verify any BIS Conformity Marking Licence (CM/L) at bis.gov.in.