Is there a way to make the screen into a costume?

I would like to turn the screen (the stage and everything on it) into a costume. I need a costume with a bunch of tiny dots, and it’d be easier to use a sprite and the pen to draw it, as opposed to clicking and barely dragging all across the sprite maker.

This is way simpler than usual, just draw a costume with the pen, and use this little script
untitled script pic 13

import this:

You don’t need a clone: