fxcss.
Documentation/Command reference
COMMAND REFERENCE

fxcss rollback

fxcss 0.22.1Source documentation

Restore the newest backup, or choose one by name:

bash
fxcss rollback
fxcss rollback --list
fxcss rollback --to chrome.backup-20260817014202

Installs and upgrades that replace an existing chrome/ keep it as a chrome.backup-*. Managed backups include the installation record, so the list can show what each one holds:

console
$ fxcss rollback --list

  Backups, newest first:

    chrome.backup-20260817014202
      AdamXweb/WhiteSurFirefoxThemeMacOS@v1.6.3
    chrome.backup-20260817014143  (the original)
      your own chrome/, from before fxcss

fxcss rollback restores the most recent, or --to <name> any of them. What was installed becomes a backup in its turn, so a rollback can itself be rolled back, and user.js follows: each version records the prefs it asked for, and rolling back to the original — the one backup with no manifest in it, because it is your chrome folder from before any of this — takes the fxcss pref block out with it.

That original is the reason upgrades chain rather than stack blindly. After five upgrades the newest backup holds the theme, not your files, so the manifest carries the original's name forward and fxcss uninstall still restores what you had before you ever ran fxcss. --keep N (default 3) prunes older backups; the original is never one of them.

Getting startedfxcss uninstall