On the job, guessing gets people hurt and puts timelines in a blender. Marking paint colors aren't just bright lines on dirt. It’s the jobsite’s version of a traffic light—fast, visual, and universal. Every can sprayed on the ground speaks the same language, thanks to the APWA’s Uniform Color Code. If you're marking, digging, or planning, here’s what every color means and how to keep your crew out of the crosshairs.
1. White – Proposed Excavation
The sketch before the dig.
White lines are the blueprint on the ground. They mark where the work is supposed to happen—before any machine fires up or post goes in. Contractors, engineers, and utility locators use white paint to show where they plan to dig. Think of it like taping out a floor before a cut—you don’t fire up the saw until the tape’s down.
Used for: Mapping out excavation zones, foundations, trenches, fence lines, or utility installs.
Why it matters: Keeps everyone on the same page and avoids dumb mistakes.
Easy way to remember: Whiteboard = game plan. Mark it before the work starts.
2. Pink – Temporary Survey Work
Here today, gone next week.
Pink is the color for measurements that might change. Survey crews use it when they’re checking elevations, property boundaries, or reference points. These marks help guide layout and placement, but they’re not final—they’re meant to be temporary. Pink’s also used when you’re not totally sure yet. It’s the “hold up, let’s double-check that” color.
Used for: Rough survey data like benchmarks, grade checks, or topography references.
Why it matters: Lets teams keep tabs on layout without messing with the site.
Easy way to remember: Pink fades fast—just like chalk on a sidewalk.
3. Red – Electric Power Lines, Cables, and Conduits
Stop what you’re doing and double-check.
Red means electricity—live wires, buried lines, junction boxes, and anything else that can fry you if you’re not paying attention. One cut here can kill someone or take out power to a block. Crews should always double-check red marks with 811 or locators before cutting. Doesn’t matter if you’ve dug there before—things change.
Used for: Electric lines, power cables, lighting conduit, signal systems carrying current.
Why it matters: You hit one of these, it’s lights out—literally.
Easy way to remember: Red means danger. Just like fire alarms and brake lights.
4. Yellow – Gas, Oil, Steam, and Chemical Lines
Warning: what’s under here can blow.
Yellow is the flag for volatile stuff—natural gas, steam, oil, chemicals. It’s not always explosive, but it sure as hell is dangerous. These lines might be pressurized, flammable, or both. If you nick one, you’re looking at fireballs or spills that shut down an entire site.
Used for: Marks lines that carry gas, petroleum, steam, or other hazardous substances.
Why it matters: Striking one of these lines can cause explosions, fires, or toxic leaks. It’s a major safety and environmental hazard.
Easy way to remember: Yellow is the color of caution and warning—think hazard tape and flashing caution lights.
5. Orange – Communication, Alarm, and Signal Lines
Don’t kill the internet.
Orange lines protect all the stuff that keeps people connected: phone lines, internet cables, fiber optics, alarm systems. Cut one and you won’t just tick off the GC—you’ll be on the hook for a full reset and possibly penalties from the cable or telecom company.
Used for: Fiber lines, telephone, alarms, signal systems, smart infrastructure.
Why it matters: Damaging these screws up networks and slows down projects.
Easy way to remember: Orange means connection. Think extension cords or network cables.
6. Blue – Potable Water
Keep the water flowing.
Blue paint flags drinking water—pipes running to homes, businesses, fire hydrants, and public buildings. Hit one, and you’re cutting off water to dozens—or triggering boil notices if you stir up the system.
Used for: Freshwater supply lines—municipal, residential, commercial.
Why it matters: Damaging potable water lines can cut off clean water to entire areas and cause regulatory violations.
How to remember: Blue is for water. Lakes, hoses, cold faucet handles—it all checks out.
7. Purple – Reclaimed Water, Irrigation, and Slurry Lines
Looks clean. Isn’t.
Purple marks water that’s not meant for drinking—stuff like reclaimed water, irrigation, or industrial slurry. It’s reused water, and it usually contains stuff you don’t want in your mouth or on your skin.
Used for: Recycled water, treated wastewater, or pressurized irrigation setups.
Why it matters: Keeps clean and dirty water systems separate, which is critical to public health and environmental compliance.
Easy way to remember: Purple’s a rare color—same with these systems. If you see purple, double-check before you dig.
8. Green – Sewer and Drain Lines
Where the bad stuff goes.
Green marks the pipes you do not want to break unless you’re a fan of cleanup and stench. These lines carry stormwater, sewage, and other drainage. Busting into one can flood your trench with stuff you really don’t want to touch. These lines often run deeper than others, so if you see green marks, expect to dig smart, not fast.
Used for: Sanitary sewer lines, storm drains, or wastewater pipes.
Why it matters: Hitting one of these can release hazardous waste and cause major cleanup and repair costs.
Easy way to remember: Green means go—but not without checking first. Don’t assume the flow is light just because it hasn’t rained.
So, Why Bother Getting This Right?
Because cutting corners here doesn’t just cause delays—it can cause injuries, lawsuits, and fines. This isn’t just paint. It’s how jobs stay safe, legal, and on schedule. Marking the ground clearly helps:
- Stop injuries before they happen
- Complies with OSHA, 811, and utility locate standards
- Speeds up site inspections and approvals
- Reduces downtime and liability
- Make sure every subcontractor knows the layout
It’s not just about marking a spot—it’s about communicating clearly before anything gets disturbed.
One Last thing...
If you’re out of marking paint or running low, don’t wait until the morning scramble. PowerPak stocks all eight APWA-approved marking paint colors. But marking paint's only half the job. PowerPak’s got the tools to lay it down faster and cleaner. The Vers-A-Striper® linestriping kart keeps pavement lines straight and saves your back. For quick hits on dirt or gravel, grab the 34" Paint Applicator Wand. Working below grade? Underground Marking Tape goes in the trench as a clear warning—so when the next crew comes through to dig, they can detect a color-coded alert before they hit anything expensive. It's a simple layer of backup that prevents major headaches.
