Firefox Themes - One per Window possible ?!?!?

[battlezoby]

I don't like to mess around with "Silly" themes, but I've been having trouble keeping track of multiple Firefox windows (with zillions of tabs each) - I'd like to one window to look one way.

Is it possible to set a Theme or Appearence or otherwise mark a Firefox WINDOW (consisting of many tabs) in a way that will make it look different than other windows?

If I could just change the color of the top-bar (the one with the [X] - close, and minimize and maximaze buttons - that would be great!

For example:

1. One for research related-to and tangenting-off-of-Topic-A, and

2. another for stuff-related-to-etcetcera-Topic B, while unfrotinately also having

3. A window for randomish stuff so assorted, it makes it hard to tell that it's my "random window" and NOT Topic-A or B. If I lose track, I'll start opening "A"'s and "B"'s in it, and end up not being able to find much of anything easily.

Actually, one answer is "Make it a private window", but that's just one specific variation and I'm not too keen on it because I'd like it keep track of my history and not be "private".

Thanks for any and all help.

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Actually, on Unix or Linux, I'd just use different desktops, Heck, on Windows 95 I just used different desktops, but I'm trying to work right now, so I don't want to mess around with a new desktops under Windows 7 right now, especially when it'll probably just go away again when Steam forces me on Win 10, Win 11, Win 12, Win 14237, etcetera in the future.

[Fajita Jim]

Private Windows have a different color scheme, it just won't save your browsing history.