> If this doesn't make the argument that Zig has certainly not defeated function coloring, I don't know what would.

if you're opting into stackless coroutines then yeah you're opting into their viral nature, but the point is that you don't have to. as the application author your dependencies won't opt you forcefully in using stackless coroutines (or any singular execution model), which is currently the case with other languages.

this is what it means to defeat function coloring.

Small marketing suggestion: maybe "limit function coloring" instead of "defeat function coloring". I like Zig's approach so far, but clearer terms would help avoid pointless arguments and disappointments that a certain proglang supremacist community loves.