Pocket Card: Cable Colour Codes — All 4 Major Standards on One Card
Printable credit-card sized reference card with cable colour codes for AS/NZS 3000, BS 7671, IEC 60446, and NEC/NFPA 70. Covers single-phase, three-phase, DC systems, historical colour changes, and medium voltage identification.
Multi-Standard4 min readUpdated March 3, 2026
Print Specifications
Credit-card size (85.6 × 54 mm), double-sided, 250–300 gsm coated cardstock, gloss or matte lamination both sides. CMYK colour mode. QR code minimum 12 × 12 mm linking to ecalpro.com/docs/reference/cable-colours.
| Parameter | Value |
|---|---|
| Dimensions | 85.6 mm × 54 mm (ISO/IEC 7810 ID-1) |
| Bleed | 3 mm all sides (final trim: 91.6 × 60 mm) |
| Safe zone | 3 mm inside trim (content area: 79.6 × 48 mm) |
| Stock | 250–300 gsm coated cardstock |
Front — Phase/Neutral/Earth Wire Colours: 4 Standards
WARNING: A RED wire = Phase A (Australia) = Phase B (old UK) = Ungrounded (NEC). ALWAYS verify the standard and era before working on any circuit.
Current Standards — Single Phase
| Conductor | AS/NZS 3000:2018 | BS 7671:2018 | IEC 60446:2007 | NEC (NFPA 70) |
|---|---|---|---|---|
| Active / Line | Red (A) or Brown | Brown | Brown | Any except W/Gn/Gn-Y* |
| Neutral | Black (N) or Blue | Blue | Blue | White or Grey |
| Earth (PE) | Green/Yellow | Green/Yellow | Green/Yellow | Green or Green/Yellow or bare |
* NEC: No mandatory phase colour. Black, Red, Blue are CONVENTION only, not code.
Three-Phase Colour Codes — Current Standards
| Phase | AS/NZS 3000:2018 | BS 7671:2018 | IEC 60446:2007 | NEC Convention |
|---|---|---|---|---|
| L1 / Phase A | Red | Brown | Brown | Black* |
| L2 / Phase B | White | Black | Black | Red* |
| L3 / Phase C | Blue | Grey | Grey | Blue* |
| Neutral | Black | Blue | Blue | White |
| Earth (PE) | Green/Yellow | Green/Yellow | Green/Yellow | Green or Gn/Yl |
* NEC phase colours shown are industry convention (not mandated by code).
Key Conflicts: BLACK = Neutral (AS/NZS) = L2 Phase (BS 7671/IEC) = L1 Phase (NEC convention). RED = L1 Phase (AS/NZS) = L2 Phase (NEC convention) = forbidden as earth.
Back — Historical Changes, DC Systems & MV Identification
United Kingdom — Changed 31 March 2004 (BS 7671 Amendment 2)
| Conductor | Pre-2004 (OLD) | Post-2004 (CURRENT) |
|---|---|---|
| L1 / Phase A | Red | Brown |
| L2 / Phase B | Yellow | Black |
| L3 / Phase C | Blue | Grey |
| Neutral | Black | Blue |
| Earth | Green/Yellow | Green/Yellow (unchanged) |
DANGER: Old BLACK neutral = New BLACK L2 phase. Old BLUE L3 = New BLUE neutral. Mixed installations require warning labels per BS 7671 Regulation 514.14.
Australia / New Zealand — Changed 2018 (AS/NZS 3000:2018 Amendment 2)
| Conductor | Pre-2018 (OLD) | 2018+ (CURRENT) |
|---|---|---|
| L1 / Phase A | Red | Red (unchanged) |
| L2 / Phase B | White | White (unchanged) |
| L3 / Phase C | Blue | Blue (unchanged) |
| Neutral | Black | Black or Blue (now permitted) |
| Earth | Green or Green/Yellow | Green/Yellow (mandatory) |
Key change: Green-only earth no longer compliant in new installations. Blue neutral now explicitly permitted (harmonisation with IEC).
DC System Colour Codes
| Conductor | IEC 60446 | NEC (Art. 210.5(C)) | AS/NZS |
|---|---|---|---|
| Positive (+) | Brown | Red* | Red |
| Negative (−) | Grey | Black* | Black |
| Mid-wire (centre tap) | Blue | White* | White |
| Earth / Ground | Green/Yellow | Green or bare | Green/Yellow |
* NEC: Colours shown are convention. Code only mandates grounded conductor = white/grey, equipment ground = green/green-yellow/bare.
Medium Voltage (MV) Phase Identification
| Standard | Method |
|---|---|
| IEC / BS 7671 | Brown/Black/Grey continue; or numbered tape: 1, 2, 3 |
| AS/NZS 3000 | Red/White/Blue continue; or letter marking: A, B, C |
| NEC | No colour mandate; tape marking at terminations required (NEC 210.5) |
| Common practice | Phase tape at each accessible point; colour or letter on cable tag |
Universal Rules (All Standards)
- Green, Green/Yellow: RESERVED for earth/ground conductor ONLY — never use for any other purpose.
- Bare conductor: Earth/ground only (unless clearly identified otherwise).
- Multi-core flexible: Core identification follows the same standard as the fixed installation it connects to.
- Mixed old/new installations: MUST have warning labels at every distribution board.
Data Source References
| Data | Source |
|---|---|
| Australian colours (current) | AS/NZS 3000:2018, Clause 3.8.1, Table 3.4 |
| Australian colours (old) | AS/NZS 3000:2007, Clause 3.8.1 |
| UK colours (current) | BS 7671:2018+A2:2022, Table 51, Regulation 514.3 |
| UK colours (old, pre-2004) | BS 7671:2001 (16th Edition), Table 51A |
| UK changeover date | BS 7671 Amendment No. 2:2004, effective 31 March 2004 |
| IEC colours | IEC 60446:2007 (now incorporated into IEC 60445:2017) |
| NEC colours | NFPA 70:2023, Articles 200.6, 210.5, 250.119 |
| DC systems | IEC 60446:2007, Section 5.2.5; NEC 210.5(C) |
| MV identification | AS/NZS 3000:2018 Clause 3.8.3; BS 7671 Regulation 514.4 |
| Mixed installation warnings | BS 7671:2018 Regulation 514.14; AS/NZS 3000:2018 Clause 3.8.1 |
Try the Cable Sizing Calculator
Put this methodology into practice. Calculate results with full standard clause references — free, no sign-up required.
Or embed this calculator on your siteFrequently Asked Questions
Each standard body (IEC, BS, AS/NZS, NEC) developed colour codes independently. IEC 60446 harmonised many countries to brown/blue/green-yellow, but legacy installations and NEC still use different schemes.
IEC/BS 7671 uses blue for neutral. NEC uses white or grey. Australian AS/NZS uses blue (harmonised) or black (legacy). Always verify before working on existing circuits.
Yes. Download, print on card stock, and laminate. Sized for credit-card format (85 x 54mm) for pocket or toolbox use. Free for personal and team distribution.