That preference is obsolete. Firefox 97 has the latest evolution of the combined preview/setup/print experience introduced in Firefox 84. The older code has been removed.

When you call up Print, there's a link on the lower right side of the overlay to "Print using the system dialog..." if the "More settings" section doesn't have what you need.

For the future:

There are bugs on file to add a new user preference and new keyboard shortcut to go directly to the system print dialog without a preview, if that's something you would prefer. Not sure whether that will arrive next month in Firefox 98 or whether it might take longer.

**EDIT** That preference became available in Firefox 101. See below.

Why do designers break things that don't need fixing...

I hate this new change and that I cannot reverse it. It is too limiting on printing options that I use to have. Why change this when it worked very well. This is just another reason why I didn't want to download the new firefox version. Plus my drop down tabs and bookmark tab has a black background, that I can't change back to white. I am highly frustrated with this and hate it. We should be able to change these settings to suit our needs! Why would you make such drastic changes? I'm tempted and probably will restore my computer to an earlier date to go back to my previous version of firefox. Firefox ARE YOU LISTENING? Obviously I am not the only person that is disappointed!

I hate this new change and that I cannot reverse it. It is too limiting on printing options that I use to have.

What was your work flow before and what are you missing? Firefox 101 added an option to skip the combined preview/setup overlay and just go straight to the system print dialog. Would you prefer that? I'll list the details below the line.

Plus my drop down tabs and bookmark tab has a black background, that I can't change back to white.

The user interface colors generally follow your theme color. If your theme has light text on a dark background, then Firefox will mimic that with the menus. Have you experimented with different themes?

Firefox 101 added a setting to skip the built-in preview/setup overlay and automatically show the system print dialog. Here's how you can try it out:

(1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button accepting the risk.

More info on about:config: Configuration Editor for Firefox. The moderators would like us to remind you that changes made through this back door aren't fully supported and aren't guaranteed to continue working in the future.

(2) In the search box in the page, type or paste print.prefer_system_dialog and pause while the list is filtered

(3) Double-click the preference to switch the value from false (use the combined overlay) to true (use the system print dialog)

If you need to restore the default display, you can call up the preference and double-click again to toggle the value back to false. There's also will be a reset arrow at the right end of the row when the preference has a non-default value.