wl-gammarelay-rs has worked for me. This is a daemon controlled through dbus, but there are some applets listed in the readme as well as a script in the repo for adjusting based on the time of day.

Apparently two years ago. Though they’ve been a “beta feature” you need to enable in the settings. I’ve yet to use them, but would be interested how others feel they compare to discord.

edit: fixed broken link

Anathem came to mind for me. Each reply naming a different book is pretty funny.