Certain states have whats called "The Purple Paint Law" which allows landowners to mark the property with purple paint instead of No Trespassing signs. This is because signs can get blown off easily from the wind and it's not far for landowners to constantly have to check on their signs.

While Louisiana isn't included as one of the states Texas and Arkansas are! Below is the full lists of states where you have to watch out for purple paint...

-Texas
-Illinois
-Missouri
-North Carolina
-Maine
-Florida
-Idaho
-Arkansas
-Montana
-Arizona
-Kansas

They chose the color purple because research says that even people who are color blind will see the color purple. For more info and what other states do you can CLICK HERE!