Electrical wire colour codes by country

Wire colours at a glance

Most of the world follows one scheme: green-and-yellow for the protective earth, blue for the neutral, and brown, black and grey for the line conductors. That scheme comes from IEC 60445 and the European cable standard HD 308, and the UK adopted it in 2004. North America is different: the US and Canada use white for the neutral and green for the earth, and the US National Electrical Code does not set colours for the phase conductors at all. The table compares AC installation wiring; DC is covered further down.

“Required” means a code or standard in force says so; “convention” means common practice that the code does not demand. Codes apply only where a government adopts them, often with local amendments, so check the edition in force where you work.

United States: NEC colour rules and conventions

For AC premises wiring, the NEC fixes only four things about colour. The equipment grounding conductor must be bare, or green, or green with one or more yellow stripes, and those colours may not be used for anything else (250.119). The grounded conductor, usually the neutral, must be white or gray, or carry three continuous white or gray stripes on insulation that is not green (200.6). The high leg of a 4-wire delta must be marked orange (110.15). And where a building has more than one voltage system, every ungrounded conductor must be identified by phase and system at every termination, connection and splice, using colour, tape, tags or another approved method, with the scheme documented or posted at each panelboard (210.5(C) for branch circuits, 215.12(C) for feeders).

The phase colours above are what most electricians install, and some owners write them into their specifications (the US Department of Defense requires black, red and blue for 208/120 V and brown, orange and yellow for 480/277 V in UFGS 26 20 00), but the Code itself leaves the choice open. NFPA’s code-making panels have said as much: in the 2011 cycle the panel described colour coding as industry practice rather than a Code requirement, and proposals to mandate phase colours were rejected in earlier cycles on the grounds that voltage testing, not colour, is what keeps people safe. Two practical points follow. A colour scheme only satisfies 210.5(C) if each colour is tied to a specific phase and system and the scheme is posted, and the same colour can mean different things in different buildings.

Neutrals, re-identification and the history of gray

• Size matters. Neutrals of 6 AWG and smaller must be white or gray along their whole length. From 4 AWG up, a conductor of another colour may be made a neutral at installation with a white or gray marking that goes all the way round it at every termination (200.6(A) and (B)). Equipment grounding conductors follow the same size break: 4 AWG and larger may be re-identified green at each end and every accessible point by stripping the insulation, colouring it green, or green tape (250.119(B) since 2023).
• Different systems in one enclosure. Where neutrals of different nominal voltage systems share a raceway, box or enclosure, they must be distinguishable, for example white for 120/208 V and gray for 277/480 V, or white with a coloured stripe, and the scheme must be documented or posted (200.6(D)). The 2026 edition also allows a white or gray conductor with a single non-green stripe as a neutral.
• White used as a hot. In a cable, a white or gray conductor may serve as a hot conductor if it is permanently re-identified at each termination and wherever it is visible, with tape or paint in a colour other than white, gray or green. In a switch loop it may only be the supply to the switch, never the switched return (200.7(C); 200.8(C) in 2026).
• Gray was not always a neutral. Until the 2002 edition the Code reserved “white or natural gray”; the 2002 NEC deleted “natural”, reserving any gray for grounded conductors, and added a note that gray may have been used as a hot conductor in older installations. In a building wired before then, a gray conductor can be live.

What changed in the 2026 NEC

The 2026 edition renumbered Article 200 (the neutral rules moved from 200.6 to 200.7, and the white-as-hot rules from 200.7 to 200.8), made orange mandatory for the high leg whatever other marking is used, deleted 230.56 as a duplicate of 110.15, moved the panelboard high-leg rule to 408.10(E)(1), added a rule for single-voltage premises at the start of 210.5(C) and 215.12(C), and added yellow with a green stripe to the colours that may never be a hot or neutral. These 2026 numbers come from NFPA’s published committee reports; we have not checked them against the printed book. The section for each rule, edition by edition:

* The 60 V dc threshold is confirmed for 2023 and 2026; the 2020 and 2023 committee reports record no change to it, so we infer the same for 2017 and 2020. To see which edition your state enforces, use the NEC adoption tracker.

Canada: Canadian Electrical Code, Part I

The CEC is far more prescriptive than the NEC. In the 2021 and 2024 editions the rules sit in Rules 4-024 to 4-030 (identified, that is neutral, conductors) and Rule 4-032 (colour coding); older guides quote 4-036 and 4-038, the numbers used in the 2015 edition and earlier. Each province adopts the code on its own schedule, sometimes with amendments, and Québec publishes its own version, so check the edition in force.

• Neutral. Up to and including No. 2 AWG, the identified conductor must be white, or carry three continuous white stripes. The 2021 edition also allowed grey; the 2024 edition removed grey. Larger conductors may be identified at each end at installation, with white paint, sleeving or tape (Rule 4-026).
• Bonding. Insulated bonding conductors up to No. 2 AWG are green, or green with one or more yellow stripes; larger ones may be marked green at each end and every accessible point. Bare bonding conductors are allowed.
• Phases. Where colour-coded circuits are required, three-phase conductors are red for phase A, black for B and blue for C (Rule 4-032). A white conductor may be used as a phase conductor only in the cases Rule 4-030 allows, such as a cable conductor permanently re-marked at every accessible point, or a switch loop.
• Utility wiring is different. Ontario’s Electrical Safety Authority warns that utilities have used white for a phase conductor, and recommends, as good practice rather than a rule, baring the consumer’s neutral at the weatherhead on three-phase services so nobody mistakes it for a phase.

United Kingdom: BS 7671 harmonised colours

Fixed wiring in the UK has used the harmonised colours since 2004. Table 51 of BS 7671 sets brown for a single-phase line conductor, brown, black and grey for L1, L2 and L3, blue for the neutral and green-and-yellow for the protective conductor. The current edition is BS 7671:2018+A4:2026, published on 15 April 2026; the previous version (with amendments 2 and 3) is withdrawn on 15 October 2026. The colours above did not change in any amendment.

The changeover. Amendment 2 to BS 7671:2001 introduced the new colours on 31 March 2004. Work started after that date could use either the old or the new colours, but not both; work started after 31 March 2006 had to use the new ones. Appliance flexes had used brown, blue and green-and-yellow since 1969 (the IET dates them to that year’s appliance colour code regulations), so the change brought fixed wiring into line with them.

Mixed colours and the warning notice. BS 7671:2018 as first published required a caution notice at or near the distribution board wherever an alteration left old and new colours side by side, warning that two versions of the regulations were present and that every conductor must be identified before work (Regulation 514.14.1). Amendment 2:2022 removed that requirement. The danger has not gone away: in a mixed installation black can be a neutral or a line conductor, and blue can be a neutral or an old L3. At the junction between old and new cables, mark conductors unambiguously (L1, L2, L3 and N sleeves or tape), as the guidance on alterations has advised since 2004. A caution label at the board is no longer required, but it costs nothing and we would still fit one.

Newer colours. Amendment 2 also changed DC and functional earth: two-wire DC is now red for positive and white for negative (it was brown and grey), with blue for a mid-wire or earthed conductor, and functional earth is pink (it was cream). Red therefore means DC positive in new UK work but an AC line conductor in wiring from before 2004.

Europe and IEC 60445

IEC 60445 is the international basic standard for identifying conductors. Its 2021 edition (amended in 2026) made the colours requirements where identification by colour is used. Only twelve colours are allowed for conductors. Blue (light blue recommended) is reserved for the neutral or mid-point conductor; AC line conductors are black, brown or grey, listed in alphabetical order with no phase sequence implied; DC conductors are red for positive and white for negative; functional earth is pink; and green-and-yellow is used for the protective conductor and nothing else, with each colour covering between 30 % and 70 % of the surface. A combined protective and neutral conductor (PEN) is green-and-yellow with blue markings at its ends, or blue with green-and-yellow markings.

In cables, the colour sequence comes from CENELEC’s HD 308 S2:2001, which set the cores that replaced the old national colours across Europe. It is still current and is listed among the harmonised standards under the EU Low Voltage Directive. Each country applies it through its own wiring rules (BS 7671 in the UK, DIN VDE 0100 in Germany, NF C 15-100 in France), so the national code decides how the IEC colours are assigned in an installation; BS 7671, for instance, assigns brown, black and grey to L1, L2 and L3.

Australia and New Zealand: AS/NZS 3000

Both countries wire to AS/NZS 3000, the Wiring Rules. The 2018 edition is current, with amendments in 2020, 2021 and 2023; the 2023 amendment revised clause 3.8.1, and the next edition is planned for 2027. The colour rules sit in clause 3.8, in Part 2 of the standard, which holds the “deemed to comply” methods. In New Zealand the Electricity (Safety) Regulations 2010 make Part 2 mandatory for domestic installations up to 80 A single-phase or 50 A per phase.

• Reserved colours. The 2018 edition prohibits green, yellow or green/yellow for an active or neutral conductor, including when a conductor is identified by sleeving. In Australia, a cable that contains active and neutral conductors may not have a green, yellow or green/yellow sheath; otherwise sheath colour is not restricted.
• Neutral. In New Zealand domestic installations black is the only permitted neutral colour (a note to Table 3.4).
• Actives. Queensland’s connection manual requires consumer mains to be colour-identified from the point of attachment through the metering, with red, white and dark blue as its example for the actives; colour-coded sleeving at least 150 mm long is acceptable, insulation tape is not. New South Wales’ service rules simply require AS/NZS 3000 colours.

We could not read Table 3.4 itself, so the rest of the scheme is unconfirmed here. Many guides give a black or light-blue neutral and red, white and dark blue actives, with red for single-phase work; check them against the current standard or your network’s service and installation rules before relying on them.

India: traditional colours and the move to IEC 60445

Indian practice has long used red, yellow and blue for the three phases (R, Y and B), black for the neutral and green, or green-and-yellow, for earth. The Central Public Works Department’s general specification for internal electrical works (2013) sets exactly that, with a green PVC earth wire run inside metal conduit, and red positive and blue negative for DC busbars.

On paper the basic standard has moved. IS 11353:2023, India’s standard for identifying conductors, is identical to IEC 60445:2021, so it carries the IEC colours. The installation code, IS 732:2019, lists IEC 60445 among its references, but its colour clause is not in the public preview, and neither is that of the National Electrical Code of India 2023 (SP 30). We could not confirm whether either now requires the IEC colours for new wiring, so expect to meet both schemes. The Central Electricity Authority’s safety regulations (2023) require earthed and neutral conductors to be permanently distinguishable from live ones, and solar AC phases and DC poles to be marked in different colours, without naming the colours.

DC and solar PV conductors

DC colours are where the systems diverge most, and where old habits are most dangerous. Under IEC 60445 and current BS 7671, DC positive is red and negative is white. In the US, the NEC’s branch-circuit and feeder rules apply to DC systems over 60 V: for 6 AWG and smaller, the positive is red or marked “+”, “POS” or “POSITIVE”, and the negative is black or marked “−”, “NEG” or “NEGATIVE”, with printed markings repeated at least every 24 inches; 4 AWG and larger may be marked with tape or tags (210.5(C)(2) and 215.12(C)(2), (C)(3) in 2026).

Solar PV circuits follow their own rules in the NEC. Since the 2020 edition, PV DC conductors must be identified by polarity at every termination, connection and splice: if they are not colour-coded, a permanent “+”, “POS” or “POSITIVE” mark for the positive and “−”, “NEG” or “NEGATIVE” for the negative. Positive conductors may be any colour except green, white or gray (the committee allowed black because sunlight-resistant PV wire often is black), negative ones any colour except green, white, gray or red, and only a solidly grounded conductor may be white or gray (690.31(B); moved to 705.25 for all DC sources in 2026). The 2017 edition required identification but no polarity colours. In Canada, Rule 64-212 of the 2021 code calls for red positive and black negative PV conductors (one source; we found no 2024 change).

Insulation colour is a weak guide on DC. Solar cable to EN 50618 (type H1Z2Z2-K) has a black sheath unless the maker and customer agree otherwise, so both poles of a PV string are often black. The international PV installation standards lean on labels rather than colours: IEC 62548-1:2023 deals with identification through marking, signs and labels, and IEC 60364-7-712:2025 has an identification clause whose content we could not read. We found no confirmed conductor-colour rule for PV DC cables in either, or in Australia’s AS/NZS 5033. Black is an AC line colour under IEC 60445 and the negative under the NEC’s DC rule, so on any DC system read the labels and polarity markings, not the insulation.

Safety: never trust colours, test before you touch

Colours record what an installer intended on the day; they say nothing about what a conductor is connected to now. Every code in this article treats colour as identification, not as proof that a conductor is dead, and the US code panels said so directly when they rejected mandatory phase colours: voltage testing cannot be replaced by a colour code. Colours mislead in ordinary ways:

• a white conductor re-used as a hot in a switch loop or cable, with the marking tape missing or faded;
• old installations: gray as a hot conductor in US wiring before 2002, red, yellow and blue phases and black neutrals in UK wiring before 2004;
• one colour meaning different things in one building, such as orange as a 480 V phase in one panel and a high leg in another;
• utility conductors coloured differently from premises wiring, such as a white phase conductor on a service;
• shared neutrals, borrowed neutrals and backfeed from generators, solar inverters or UPS systems, which can make a correctly coloured conductor live after its breaker is off;
• DIY and non-compliant work that follows no scheme at all.

The safe sequence is the same everywhere: identify the circuit, isolate it and lock it off, then prove it dead at the point of work with an approved voltage tester, and check the tester on a known live source or a proving unit before and after the test. The UK Health and Safety Executive’s guidance (HSG85) sets out that sequence, including testing the instrument before and after use. In the US, OSHA 1910.333 requires a qualified person to verify with test equipment that circuit parts are de-energized, and above 600 V to check the tester immediately before and after. Treat every conductor as live until your own test says otherwise.

For sizing the conductors whose colours are covered here, see the wire size and ampacity chart. The guide to electrical codes by country explains which code applies where, and network cabling follows its own colour order, covered on the RJ45 pinout page.

How we checked: NEC requirements and their section numbers come from NFPA’s own committee reports for the 2020, 2023 and 2026 revision cycles; Canadian rules from CSA’s memoranda of revisions and the Ontario Electrical Safety Authority; UK rules from IET and SELECT publications on BS 7671; IEC and European rules from the IEC webstore and the EU’s list of harmonised standards. We summarise requirements in our own words. Where a fact rests on one source we say so, and where we could not confirm one we left it out.