Click on the shape that you want, set the saturation, transparency, and brightness to the right level, and press space as you watch your void spiral into construction, you can change the sliders during the creation, to make things interesting.
I actually first created this code in Python with Turtle, so I thought I would try porting it to scratch. It works, by simply repeating different shapes, but with each angle, 1 degree less than normal, creating a sort of spiral effect. Enjoy. New Game - https://scratch.mit.edu/projects/360997344/