But it's for a good cause.
If a child comes to your door with a blue pumpkin, it may mean the child has autism and is unable to speak.
Omairis Taylor didn't start the initiative, but her Facebook post has been shared more than a hundred thousand times.
Parents hope it prevents uncomfortable encounters, when people don't understand why kids don't talk.
"Nobody wants to have to stop and say to a stranger in the store, oh, he's not responding to you because he's on the autism spectrum," says Nicole Taylor.
Parents say a little awareness could make for happier Halloweens.