It all just looks like ordinary black on white to me. Somebody else was was complaining of blurry text, also not obviously in evidence on my PC (Firefox, Windows) or iPad, so perhaps browser-dependent.

On iPhone, it is an emissive yellow-orange on black. Very hard to read.

Edit: not just hard to read, but physically painful. I noped out of reading TFA because it’s not worth using my limited eye strain budget for the day.

Doesn’t your browser have a reader mode? E.g. both Firefox and Safari has such modes.

It changes based on the `prefers-color-scheme` CSS media query. When the value is `dark`, the page shows a yellow font with an orange glow over a dark background, otherwise it shows black on white.