Terminal version of prefers-color-scheme

[cor]

prefers-color-scheme is a feature that lets websites know if the user has their OS set to dark mode or to light mode. It works very well: if you toggle the system setting, most websites change their color scheme.

Terminals are lacking in this regard. There is no standard way to communicate to TUIs and CLIs what color scheme the user has set. It would be amazing if we could create a terminal version of prefers-color-scheme that TUIs can integrate with, so that if a user switches to light mode in their OS settings, Helix, Zellij, Yazi, etc all switch to light mode too.

EDIT: apparently there is already a spec for this!: https://github.com/contour-terminal/contour/blob/master/docs/vt-extensions/color-palette-update-notifications.md

[cor]

Special case to take into consideration is how this will work over SSH: if the host switches to light mode, the server that is SSH'd into needs to somehow also get this info

[00-kat]

The application running through SSH has no idea it's not on a local machine¹; it all works out transparently because terminal programs communicate with the terminal with in-band text.

Footnotes

1. Well, it can check for SSH-specific environment variables of course. ↩

[00-kat]

https://github.com/contour-terminal/contour/blob/master/docs/vt-extensions/color-palette-update-notifications.md?

[cor]

Looks like exactly what I was looking for, and apparently Ghostty already implements this! Exciting development