Hi, recently you made an internal change to only create sharestones for specific (the vanilla) dyes, instead of just any present DyeColor values.
I made a mod ("dye the world") a few months back that adds support between the mod "dye depot" and various other mods, including this one. It adds models and data for sharestones with that mods dyes.

While your change makes sense and is a lot cleaner, this of course does not work now anymore, since these blocks do not get created anymore. I have to take a closer look at the code again, but I was wondering if to make it work again, I would need an API on waystones side to allow more colors, which I could call from my compat mod?

Merely adding models was not enough to make a functional sharestone even prior to the change, since the colors aren't just decorational but open up their own waystone type/visibility and register individual warp requirement conditions.

There may be an API that makes it easier to add new waystones/sharestones in the future, but the plan for sharestones is to move away from colors entirely, and instead scope them through a precious material like in the Bedrock version, probably by Minecraft 1.22.

Right, I think I needed to mixin somewhere along the way into one of waystones classes too. That might work again for the new version, but I was wondering if you'd be open in offering some form of API so I could solve it in a less hacky way.
I would also be open to create a PR for it with a potentiell solution, I don't think it would be much.