Single colour vector graphics

The previous attempt at vector grqaphics results in some pretty chunky files (lots of vectors to render), and I'm worried it will cause issues in the combined book. I've tried something simpler now, with just the outline filled in in black. I think it will work just as well, and potentially distract less from the message I'd be trying to get across.

I'm also not sure whether I want to give them more of a mob-like appearance by rotating them by increments, as in the other picture.