If you’ve ever seen a purple fence or tree mark and wondered why—it’s not just a quirky paint choice. In many rural areas, purple means one clear thing: no trespassing. The color serves as a legal warning in several U.S. states, replacing traditional “Keep Out” signs that can fade or fall off.

Rules of the Paint
There are guidelines for using this color code.
The paint must form vertical stripes at least one inch wide and eight inches long, placed 3–5 feet off the ground so they’re easy to spot.
Marks should appear every 100 feet to clearly outline private property.

Not Everywhere Recognized
Purple paint laws differ by state. Some states fully recognize them, others don’t—so landowners should check local regulations before painting.

A Simple but Effective Signal
It may look odd, but purple paint works. It’s bright, unique, and easy to notice. So next time you spot a purple fence or tree mark, take the hint—it’s there to tell you to stay out.