What inserts are you using? To get the rainbow effect you want to minimize the distance between cut spikes width, without wiping out all of the cut spike, so a really pointy insert at enough FPR to create a "diffraction grating effect". If you want them to look polished, go with a wide insert...
Just need a big enough lathe and the right tool holder. G-code is G-code, unless its a Siemens control, those things run their own language and while it looks kind-a-like g-code, it's not.
OH! Now the link works. Cheater Cheater you use a biga$$ lathe!
I thought you actually some crazy kraut space magic thing going on.
In my best Yoda
Impressive, that is.
The lay lines you've kept. Over-polishing the corners, you have not.
What sorcery is this that doesn't require a lathe?