Неопределенная управляющая последовательность \textcolor

[Ethsim2 (Ethan)]

Вы правы. Похоже, это действительно исчезло после

Upgrading Mathjax to version 4

@sam and all interested in typing math in Discourse. I’ve updated the discourse-math plugin so that it uses MathJax V3, rather than the much slower and very outdated V2. As expected, the result is a much snappier user experience, while still maintaining the feature rich environment as compared to KaTeX. I’d love to issue a pull request, if you think the results look good. You can see it in action on my class Discourse site: Most of the content on that site is private or unlisted. There sho…