The DC wire color code focuses on different wires from AC, with specific functions, not just a regular hot, neutral, ground setup.

Here are the basic color code requirements for DC wires as per NEC Article 250:

• Red: Used for the positive (+) wire in nearly all DC systems (battery, solar, automotive, electronics). In Europe, as per IEC standards, positive wire is Brown.

• Black: Used for the negative (–) wire in all DC systems, returns current to the power source. In Europe, it is Blue.

• Green or Bare (uninsulated): Used for the safety ground (equipment ground or chassis ground). It carries fault current to earth. Aside from green, it can be Yellow in Europe.

• White or Gray: Used as the grounded conductor or neutral, only present in grounded DC systems like building-scale solar arrays or industrial battery banks.

• White, Gray, or sometimes Black: Used as return/common in low-voltage electronics when not using just red and black. In this context, the return/common wire carries current back to the power source (usually the negative side) and completes the circuit.

The color code for 12V and 24V DC systems is generally the same, with no differences there. The differences mainly depend on the type of ground and neutral used. Neutral is less common in DC setups than it is in conventional ones.

Standard DC Color Code

Industrial or Solar DC Systems Color Code

DC Power Applications

• Battery-powered devices like phones and laptops

• Solar power systems (charge controllers, inverters, batteries)

• Cars, trucks, and motorcycles use 12V or 24V DC systems.

• Backup power supplies (UPS) and server racks often run on 48V DC in data centers

• DC motors for conveyor belts, robotics, and automation

• Medical equipment and batteries

• Aircraft and ship internal systems

Cables for DC Applications

If the application calls for a different color-coding than that of a manufacturer's warrants, labeling and marking are an adequate choice.

• PV Photovoltaic Wire (600V, 2000V)

• DLO Diesel Locomotive Cable (DLO) 2000V - suitable for both AC and DC

• Welding cable: carries DC for welding-specific functions

• Hook-up wire: low-voltage cable for DC electronic applications

• Automotive wire (GPT, TXL, TWP, SXL, GXL, GPT) - DC-only.

• Battery cable ( SGT, SGX, STX) - DC-only.

• Marine Battery Cable

• Speaker Cables