If you have opened your electrical panel or peeked into the attic of a newer Central Florida home, you have probably noticed that the plastic-sheathed cable (most people call it by the brand name Romex®) comes in different colors. Those colors are not decoration. Since 2001, most manufacturers color-code the outer jacket so the wire size, and therefore the circuit size it belongs on, is visible at a glance. Here is what each color means and what it can (and cannot) tell you about your home.
The Romex wire jacket color code at a glance
| Jacket color | Wire size | Typical circuit | Where you usually see it |
|---|---|---|---|
| White | 14-gauge | 15-amp circuits | Lighting and general-purpose receptacles |
| Yellow | 12-gauge | 20-amp circuits | Kitchen, bathroom, laundry and garage receptacles |
| Orange | 10-gauge | 30-amp circuits | Water heaters, dryers, some A/C equipment |
| Black | 8- or 6-gauge | 40–60-amp circuits | Ranges, larger A/C, EV chargers, subpanel feeds |
| Gray | varies | varies | UF-B underground/outdoor-rated cable (direct burial) |
Three important caveats before you trust the color
1. The printing on the jacket is the real authority
The color convention is voluntary: it comes from the manufacturers, not the National Electrical Code. The NEC cares about the conductor size and insulation type, which is printed in text right on the jacket (for example “NM-B 12-2 W/G”). When we verify a circuit, we read the print, not the paint.
2. Homes wired before 2001 do not follow it
Color coding arrived in 2001. In older Orlando-area homes the sheathing is usually white, ivory, or black regardless of wire size, so a white jacket in a 1985 house tells you nothing about the gauge inside. That is one reason panel work in older homes starts with verification rather than assumptions.
3. Jacket color is not the same as conductor color
Inside any of these cables you will find individually colored conductors: black (and sometimes red) for hot, white for neutral, and bare copper or green for ground. Those inner colors follow a different, code-driven convention and mean the same thing no matter what color the outer jacket is.
What the colors are useful for as a homeowner
A quick glance at the cables entering your panel can tell you a lot about how your home was wired: yellow cable feeding a 20-amp kitchen circuit is what you want to see; a 15-amp-sized white cable landed on a larger breaker is a mismatch worth having checked. Color also helps our electricians trace circuits faster during a safety inspection, and it makes undersized wiring stand out during panel upgrades in homes that have been renovated a few times.
Common questions
Can a 20-amp breaker protect white 14-gauge Romex? No, a 15-amp circuit belongs on a 15-amp breaker. Pairing a larger breaker with smaller wire lets the wire work harder than it is rated for, which is exactly what breakers exist to prevent. It is a common finding in DIY-renovated homes and a quick fix for an electrician.
Does gray always mean outdoor? Gray is the convention for UF-B (underground feeder) cable, which is rated for damp locations and direct burial. Indoor NM-B should not be used outdoors, whatever its color.
My whole house has white cable. Is that bad? Not by itself. It usually just means the home predates the 2001 color convention. What matters is whether each circuit’s wire size matches its breaker, something a whole-home electrical inspection verifies in an afternoon.
When to bring in a licensed electrician
Reading jacket colors is a great homeowner skill; working inside a panel is not a DIY project. If something in your panel does not look right (mismatched sizes, double-tapped breakers, or cables you cannot identify), Thomas Edison Electric’s licensed electricians (FL EC13015487) can inspect it and give you a written, plain-English rundown. Book online or call the office.
The standards referenced in this article come from the National Electrical Code (NFPA 70), which guides how licensed electricians size and protect residential circuits.