Click the flag. After a few seconds, the colors should start to spiral into itself. (Turbo mode is highly recommended)
This was done with a single pen. Music is PowerBreak by Elexive. Code was is a heavily modified version of Girlscanprogram's spiral art code. It's almost impossible to tell similarities unless you look directly at the code. I made the thumbnail (Before you comment that this isn't a spiral, hear me out. This uses a spinning circle system that spins so fast and fades color so well, it's almost impossible to notice the spiral. Towards the middle meanwhile, you'll start to see the spiral more as the lines come closer together.) (TL;DR: The spiral is only really visible in the center)