There is no universal color for L1, L2, and L3; colors depend on the standard and context. For three-phase power, common schemes include IEC: L1 brown, L2 black, L3 gray; and North American practice: L1 black, L2 red, L3 blue. In other contexts, colors can vary by device or manufacturer.
Understanding which colors apply requires knowing the regional standard, the era of installation, and the equipment involved. This article surveys the most widely used conventions and the main exceptions you’re likely to encounter in electrical work and equipment labeling.
Three-phase power color codes by region and standard
Overview of common schemes used for the live conductors in three-phase wiring.
IEC/European standard
The International Electrotechnical Commission and many European installations follow brown for L1, black for L2, and gray for L3.
- L1 — brown
- L2 — black
- L3 — gray
Note: Some older European sites may still show red, yellow, blue for L1/L2/L3, so always verify on-site documentation or cable jackets.
North America (NEC/NFPA) standard
In the United States and Canada, the typical three-phase color assignment is black for L1, red for L2, and blue for L3.
- L1 — black
- L2 — red
- L3 — blue
Region-specific variations can occur in facilities that borrow cables from different suppliers or regimes; check the installation drawings and labeling.
Australia and other regions
Many regions aligned with IEC practices. In Australia, the live conductors are commonly L1 brown, L2 black, L3 gray, consistent with the IEC approach.
- L1 — brown
- L2 — black
- L3 — gray
Always confirm against local standards (AS/NZS 3000) and the project wiring diagrams.
Other contexts where L1/L2/L3 colors appear
Beyond three-phase power, labeling with L1/L2/L3 is less standardized and often vendor- or device-specific. Here is what you should know.
- Electrical equipment panels and motor starters: color schemes vary by manufacturer and region; refer to the device’s wiring diagram and labeling on the panel.
- DC or mixed circuits in some equipment: L1/L2/L3 may be used as designators for different power rails or channels, with colors chosen by the manufacturer; always consult the product manual.
- Non-electrical contexts (for example, data channels or labeling schemes in fiber or control logic): colors are not standardized across the industry and should be taken only as a guide from the specific vendor.
In all cases, if you’re unsure, locate the equipment’s labeling, consult the project drawings, or verify with a qualified electrician or technician.
Summary
Colors for L1, L2, and L3 are not universal. The most widely used schemes are IEC/European (L1 brown, L2 black, L3 gray) and North American (L1 black, L2 red, L3 blue), with historic variations such as UK red-yellow-blue and regional adaptations like Australia’s brown-black-gray. Always verify against local codes, on-site labeling, and the wiring diagram before working with any three-phase system.