Possible luacolor bug or something - TeX

TopAnswers TeX

Meta

Databases

TeX

Code Golf

APL

C++

.net

db<>fiddle

Java

*nix

PHP

PowerShell

Python

Rust

टेक्-मराठी

Typst

Web Client Dev

Web Server Dev

Possible luacolor bug or something

add tag

nsajko

This renders `(5x`, but if the usage of `luacolor` is removed, the output is `(5x)` as expected.
```
\documentclass{scrartcl}
\usepackage{mathtools}
\usepackage[svgnames]{xcolor}
\usepackage{luacolor}
\begin{document}
  \( ({ \mathcolor{Fuchsia}{5} })x \)
\end{document}
```

How so?

Top Answer

nsajko

Fixed in latest TeXLive, the issue on Github seems to be https://github.com/ho-tex/luacolor/issues/7

Giving an update on this: The kernel team is aware of this. The issue stems from the way colours are set with `luacolor` and without it: The normal approach using whatsits uses `\aftergroup` to reset the colour at the end of the group (as the colours used this way aren't contained by groups), whereas this `\aftergroup` isn't necessary in `luacolor` as colours set with it are indeed contained by groups. Since `\mathcolor` avoids using groups it issues an `\aftergroup` to remove the colour restoring macro placed by the normal approach (that is unnecessary since `\mathcolor` resets the colour itself without a group) before using `\color`. This removes the `)` in your example (as the only group is the one you mistakenly placed). For the time being you could use `\textcolor` instead of `\mathcolor` (you'll have to be careful, as `\textcolor` might affect the spacing of your maths by putting `{}` around atoms).

@nsajko, re: [your question](#question), the whole point of `\mathcolor` is to avoid putting extra groups around stuff so that the spacing isn't wrong, so your input should look like `\( (\mathcolor{Fuchsia}{5})x \)`. With that out of the way: It seems there is indeed an incompatibility between `luacolor` and `\mathcolor`. I'll prod the "right" people to this thread.

1 Answer