Terminal on Ubuntu Server 24.04 via PuTTY - where to change text colors?

[Bo Berglund]

I have a pair of 24.04 Ubuntu servers, which I mainly interface with using PuTTY
on Windows. I also use PuTTY against my many Raspberry Pi units.

I have long wondered about the display of file lists (ls -la) where certain
files get text colors depending on their extension...
And if I use nano to edit a script file it shows different colors if the file is
set to be executable or not...

I don't like the selected colors so I want to change them, but where?
Is it something done in PuTTY or is it an Ubuntu setting and/or nano setting?

In both cases where can I get the file listing to show the files with a single
color (white on black)?

And is the coloring when editing using nano a nano setting (where is that done?)
or an Ubuntu general setting (again where to adjust?)?

In my view a command line interface should not use hard to read coloring at all,
white on black or black on white should be the default.

Now I get varying results for different devices I connect to with the worst
being dark blue on black (almost impossible to read).

Please help, I have been using PuTTY against Linux only for about 15 years so I
don't know how to handle this....

Right now it colors mp4 files violet for some unknown reason....

TIA


-- 
Bo Berglund
Developer in Sweden