NM-B cable, known under one of its brand names, Romex, is a non-metallic sheathed cable used for indoor residential and light commercial wiring. The cable consists of a PVC outer jacket, 2 or 3 insulated conductors (black, white, red), and a bare copper ground wire. The connector’s outer insulated jacket has traditionally been color-coded white, yellow, orange, or black, depending on the cable size. However, in 2024, new colors were added to pink, purple and pink, to differentiate between two-conductor and two-conductor cable configurations.
Currently, the outer shell colors of the NM-B Romex cable are as follows, depending on the cable size:
14 AWG /2 → White — 15 amps
14 AWG /3 → Blue (new in 2024) – 15 amps
12 AWG /2 → Yellow — 20 amps
12 AWG /3 → Magenta (new in 2024) – 20 amps
10 AWG /2 → Orange — 30 amps
10 AWG /3 → Pink (new in 2024) – 30 amps
8 AWG /2 and /3 → Black – 40 amps
6 AWG /2 and /3 → Black — 55 amps
Before the update, each size was the same color, regardless of the number of connectors. For example, 14/2 and 14/3 were yellow, 12/2 and 12/3 were yellow, etc.
Romex wire color chart history
The Romex color system in common use since 2001, before the update was:
• White → 14 AWG
• Yellow → 12 AWG
• Orange → 10 AWG
• Black → 8 AWG (and sometimes 6 AWG).
The NEC or other similar legislation has not mandated this color system. It was first described in NEMA’s “Bulletin No. 94 – Type NM-B Cable Sheath Color Coding for Conductor Sizing” issued by NEMA in 2001, and has since been accepted as part of general industry practice.
However, the NEMA Bulletin also states that this color coding is not required by NEC or UL 719, and that NM-B cable may be manufactured without conforming to this color coding. In other words, jacket color is a useful convention, not a symbolic mandate. Use of the color coding system, whether old or new, is voluntary. The label on the packaging that directly shows the cable size is more important than the color.
The logic behind the new 2024 Romex cord colors
The introduction of blue (3/14), magenta (3/12) and pink (3/10) colors to the Canon NM-B Romex is a manufacturing-led initiative. In 2024, it was adopted by manufacturers Soutwire and Cerrorwire and was quickly picked up by other companies in the industry. This is intended to reduce installation errors, such as pulling the wrong cable, and make it easier to distinguish two-conductor versus three-conductor cables remotely. The latest version of the NEMA bulletin did not mention the new colors, but they have been approved.
Older versions of NM-B Romex cables from the NEMA Bulletin are still usable (eg 10/3 orange, 12/3 yellow). You don’t have to replace cables, and you can still buy the old color versions where they are available; It’s just that the updated color code is more convenient.
Guide to Romex sizes
Here’s a quick guide to every Romex size and color to eliminate the confusion. The three connector configurations that are getting new colors in 2024 are used in multi-way switches to control lighting from multiple locations, custom circuits with multiple neutral temperatures, multi-wire branch circuits, and other applications:
White jacket
14/2 NM-B
Enough:14 AWG
amp: 15 A
Uses:
Notes:
Blue jacket (New in 2024)
→ 14/3 NM-B only
Enough:14 AWG
amp: 15 A
Uses:
3 or 4 way light switch settings
Ceiling fans with separate light/fan control
Multi-wire branch circuits need two heat + neutral points
Yellow jacket
→ 12/2 nm-B
Enough:12 AWG
amp: 20 A
Uses:
Notes:
Still used for 12/2
Also previously for 12/3
Purple jacket (New in 2024)
→ 12/3 NM-B only
Enough:12 AWG
amp: 20 A
Uses:
Split wire bowls (upper/lower are controlled separately)
MWBCs (multi-wire branch circuits with a common neutral)
3-way switches in kitchens or large spaces
Orange jacket
→ 10/2 nm-B
Enough: 10 awg
amp: 30 A
Uses:
Electric water heaters
Clothes dryers
Air conditioning units
Baseboard heaters
Notes:
Pink jacket (New in 2024)
→ 10/3 NM-B only
Enough: 10 awg
amp: 30 A
Uses:
240V double load appliances with control wiring
Electric heater + fan/light combo units
240 volt circuits with thermostats for pilot service
Black jacket
→ 8/2, 8/3, 6/2, 6/3 NM-B
Enough:8 or 6 awg
Amps:
Uses:
Electric ranges
Double ovens
Large subpanels
Tankless water heaters
Notes:
Nassau National Cable stocks all sizes Romex NM-B cable In both new and old colors, so you can choose what you like best.
