Firefox Portable

how do you change toolbar background color? i cant get good contrast. thx
i try in themes but dont find any option and changing theme doesnt bring wished color.
nor of the setting or themes get met to black background, i need to find other way.
i afraid i have to find a way in about config, as not having consistent color for all background.
i kinda try to get black for all backgrounds.
how do i get it?
thx
EDIT
this could possibly do...
but they forgot to put the name of the html or css file to change it in.

I just tried opening a link from TB portable, but it said FF was already running and I need to close it to open a FF portable. I did, checked the shortcut I use that points to portable FF location and the link opened, but in the opened browser About FF said it was FF, not portable like it used to say. Does it mean I'm actually running regular FF? It forced 2 updates on me so I don't know what happened - now it's v.115.
Thank you for a quick reply.

Firefox is Multilingual now. Language can be switched or added in Settings -> Language -> Set Alternatives... -> Select a language to add... -> Search for more languages... -> Select a language to add....
So no need to create so many different language versions anymore.

How many separate copies of Firefox can you run continuously without causing problems in the browsers' functionality? It's like cloning applications.

Is it possible to reduce the tab bar and the address bar? It takes up a lot of space on the screen.

Firefox updates several times a week. Why so many? Maybe it does a general update, say, once every two weeks? Or maybe once a month.

strange action with Mozilla Firefox® ESR, Portable Edition
Version 128.8.0 for Windows 7 x64, English

I found my 115.15.0 esr (64-bit) was saying message about updating due to need to verify extensions....

so I downloaded the Version 128.8.0 as above, and started that..
nothing seemed to happen, but now my 115.15.0 esr (64-bit)
is now having no problem with 'verifying extensions'...

no idea why firefox portable shows now site cookie settings all in same color.
the whole buttons are in same color, example black.
you cant recognize the setting, yes or no.
no idea whats wrong.
one tech site settings, i get not so often cookie requests.
its very bad as i have to set it.
tried other windows themes and user customized but doesnt help.
firefox setted to use windows theme.
any ideas what the hell is with it?!
million thanx!

i had to quick stop portable firefox to use huge system ressources, also drive space!
out of disc space...
i'm thinking/asking (myself) if some setting or profile problems, or whatever makes it to use and/or block disc space.
i have to check if it saves some cache unasked on system drive.
this is first idea...

2nd idea, saving/using system space as/like ram...

first check shows some GB of crash reports and default profiles...