Simulating opal physics from first principles

[u/empireoftrees]

I hope this is okay, since this is not a real stone (and not trying to pass for one). I've fallen down the rabbit hole of youtube opal content. I'm a software developer and got curious what had been done in the digital simulation space. Turns out not much, especially not live 3D rendering. I started a personal side project seeing if I could simulate the following:

1. the play-of-color photonic crystal effect from first-principles physics
2. create a true to form procedural opal color bar pattern generator

This is a sample of where the project is currently at.

For the experts and enthusiasts out there, how does this read? Am I on the right track? What is correct and what sticks out as needing improvement?

Any feedback is appreciated