pantheon-tweaks VS switchboard

Pantheon Tweaks Guide

As for the windows, you can modify those using gtk themes. You'll first need to install Pantheon Tweaks, then go to gnome-look.org to download and install GTK3/GTK4 themes (the OCS-URL method is most convenient). Once you've installed a theme you can apply it from Pantheon Tweaks. You can also install icon themes from that site.

For elementary 6 it's Pantheon Tweaks: https://github.com/pantheon-tweaks/pantheon-tweaks

Pantheon tweaks https://github.com/pantheon-tweaks/pantheon-tweaks can force dark mode in apps.

https://github.com/pantheon-tweaks/pantheon-tweaks Is this the Pantheon Tweaks app you were searching for?

You should install Pantheon-tweaks, just type this in your terminal:

First install Pantheon Tweaks to be able to change appearance of Pantheon environment.

Purge the old Tweaks: sudo apt purge elementary-tweaks Remove PPA : sudo add-apt-repository --remove ppa:philip.scott/elementary-tweaks And : sudo apt update Then check in the App Center if the update should be done. The new Tweaks : https://github.com/pantheon-tweaks/pantheon-tweaks

try building from src https://github.com/pantheon-tweaks/pantheon-tweaks

This should be what you are looking for

If you use Elementary OS, you should know that the settings app isn't gnome control center but switchboard. And switchboard actually doesn't come with settings, it is just a panel where you can find the settings called "plugs". If some plugs mysteriously disappeared, you may start to understand what happened (It is uninstalled).