The main reason behind the coloring of electrical wires is to identify the purpose of using them, only by looking at them. It is very important to use the right wire in every connection of electrical wiring. It gives safety, efficient use, and also increment in durability. The commonly used colors in electrical wiring are red, green, and black.
Red-colored wire: this is a live wire in the circuit. This wire can not be connected to any other red or black colored wire.
Green-colored wire: this is the wire used for grounding or earthing in the circuit. A green wire can be connected to another green wire. This green wire provides the path to the extra charge to the ground.
Black-colored wire: black wire is a neutral wire. In the connection of the neutral bus bar used for distribution, this neutral wire is used. The neutrality of the wire permits to connect to another black wire.
The topic of the color code of electrical wiring is vast and important. Every country has its color code for electrical wires. Also, the wires used in AC and DC power circuits have different color codes.
The color codes of wires of some countries are tabulated below.
Wire color code – India
| Circuit Type | Color | Function | Label |
| AC power circuit (single-phase) | Green | Protective Earthing | PE |
| AC power circuit (single-phase) | Black | Neutral | N |
| AC power circuit (single-phase) | Red | Line | L |
| AC power circuit (three-phase) | Red | Line | L1 |
| AC power circuit (three-phase) | Yellow | Line | L2 |
| AC power circuit (three-phase) | Blue | Line | L3 |
| AC power circuit (three-phase) | Black | Neutral | N |
| AC power circuit (three-phase) | Green or Green-yellow | Protective Earthing | PE |
Wire color code – Regions of Europe
| Circuit Type | Color | Function | Label |
| AC power circuit | Green-yellow | Protective Grounding | PE |
| AC power circuit | Blue | Neutral | N |
| AC power circuit | Brown | Line, used in single phase | L |
| AC power circuit | Brown | Line, used in three phase | L1 |
| AC power circuit | Black | Line, used in three phase | L2 |
| AC power circuit | Grey | Line, used in three phase | L3 |
| Circuit Type | Color | Function | Label |
| DC power circuit | Green-yellow | Protective Earthing | PE |
| DC power circuit | Brown | Positive in the unearthed two-wire system | L+ |
| DC power circuit | Grey | Negative in the unearthed two-wire system | L- |
| DC power circuit (two-wire system) | Brown | Positive of the negative earthed system | L+ |
| DC power circuit (two-wire system) | Blue | Negative of the negative earthed system | M |
| DC power circuit (two-wire system) | Blue | Positive of the positive earthed system | M |
| DC power circuit (two-wire system) | Grey | Negative of the positive earthed system | L- |
| DC power circuit (three-wire system) | Brown | Positive | L+ |
| DC power circuit (three-wire system) | Blue | Mid-wire | M |
| DC power circuit (three-wire system) | Grey | Negative | L- |
Wire color code – Regions of the USA
| Circuit Type | Color | Function | Label |
| AC circuit (120/240 volts) | Black | Line (single-phase) | L |
| AC circuit (120/240 volts) | Black | Line (three-phase) | L1 |
| AC circuit (120/240 volts) | Red | Line (three-phase) | L2 |
| AC circuit (120/240 volts) | Blue | Line (three-phase) | L3 |
| AC circuit (120/240 volts) | White | Neutral | N |
| AC circuit (120/240 volts) | Green or bare | Protective Ground | PE |
| Circuit Type | Color | Function | Label |
| AC circuit (277/480 volts) | Brown | Line (three-phase) | L1 |
| AC circuit (277/480 volts) | Orange | Line (three-phase) | L2 |
| AC circuit (277/480 volts) | Yellow | Line (three-phase) | L3 |
| AC circuit (277/480 volts) | Grey | Neutral | N |
| AC circuit (277/480 volts) | Green or bare conductor | Protective Ground | PE |
| Circuit Type | Color | Function | Label |
| DC circuit (2 wire ungrounded) | Red | Positive | L+ |
| DC circuit (2 wire ungrounded) | Black | Negative | L- |
| DC circuit (2 wire negative grounded) | Red | Positive line | L+ |
| DC circuit (2 wire negative grounded) | White | Negative line | L- |
| DC circuit (2 wire positive grounded) | White | Positive line | L+ |
| DC circuit (2 wire positive grounded) | Black | Negative line | L- |
| DC circuit (3 wire grounded) | Red | Positive line | L+ |
| DC circuit (3 wire grounded) | White | Centre tapped middle line | M |
| DC circuit (3 wire grounded) | Black | Negative line | L- |
| DC circuit | Green | Ground | G |
Wire color code – Regions of the UK
| Circuit Type | Color | Function | Label |
| AC circuit | Brown | Single-phase line | L |
| AC circuit | Brown | Three-phase line | L1 |
| AC circuit | Black | Three-phase line | L2 |
| AC circuit | Grey | Three-phase line | L3 |
| AC circuit | Green-yellow | Protective earth | PE |
Wire color code – Canada
| Circuit Type | Color | Function | Label |
| AC circuit | White | Neutral | N |
| AC circuit | Black or Red | Single-phase line | L |
| AC circuit | Red | Three-phase line | L1 |
| AC circuit | Black | Three-phase line | L2 |
| AC circuit | Blue | Three-phase line | L3 |
| AC circuit | Green or green-yellow | Protective ground | PG |
Author
Sunmoni Gohain
NIT Silchar
Thank you for the tables. It’s a very clear and informative presentation. Differentiation by country of origin was also a stroke of genius. Brilliant article!