Welcome to Color Laser 1.0.1! Where ever you move your mouse paint will follow. Hold down the mouse to turn the Color Laser on or off. The colors the the "laser" "burns" into the screen are completely random, so have fun making designs that look like they are from another world.
I was wondering how you could make pictures on Scratch when I thought of the idea of making pictures with random colors. After that I found Splash Paint v0.2 by @Gamehutsoftware (though I didn't take the actual coding, so this is not a remix). Notes: Try moving the mouse around the screen a couple times, and see what happens.