i wouldn't then i would scuff it or something

You wouldn't paint it. You'd use chalk. Chalk washes away.
People can do that kind of stuff, as long as it's not permanant. If it's permanant, it's called vandalism & they'll get arrested.

And it has to be done in a day. If they stop in the middle, go home & come back to finish it the next day, some fool will fuck it up.

Really! in New York thats so cool!

I know it's cool !! (j/k)