Hello, I need your help and skills .
I would like to hide some words or a shape like in this video (I am trying to keep busy some kids with a game, I will print and hide the messages all over the house and let the kids read the messages with a red filter). But I would like to do it inside Paint.net. I copied the code to CodeLab but it did not work. I tried using Pixelate, adding Noise, playing with layers but I have had no luck.
This is the video:
This is the site where I found the code: