I just realized that I'm not sure if it's Borland or Norton who brought the blue interface to DOS first. Does someone remember who was first?
For some whom miss this deep blue and cyan. https://play.tirreno.com/game
Not sure about the blue color specifically but almost all the conventions came out of IBM's SAA and CUA initiatives. There is still a lot to find about these conventions and for some time in the early 90s every computer mag wrote about them. When I searched for the original IBM sources a while ago I could not find anything.
So, if anyone has a pointer to the original style guide I'd be very grateful.
"Borland's DOS IDEs represented what we might call brutalism in interface design."
Hmm, I think they could be perceived as brutalist nowadays because people are not aware of the technical restrictions these applications had to work with, but at least Turbo Pascal was a marvel of beauty at the time.
"Windows (after 2000) arbitrarily became more like favelas with dozens of unnecessary panels in every application, a great example of when features win over rationality."
I'd call it a slum. The Favela is X11 - poor by definition, yet charming in places, sometimes dangerous.
Norton Commander released its blue interface in 1986 (1), when Borland Pascal didn't have released something that had similarities with Norton Commander one year later in 1987, it was Borland Pascal 4.0 (2). And here is Pascal 3.0 for comparison (3).
UPD:
But now I'm not sure that it was NC first. Here is PathMinder (4) from 1984 and IBM FileCommand (5) 1983.
(1) https://winworldpc.com/res/img/screenshots/1x-6e0aba060e5238...
(2) https://dosdays.co.uk/media/borland/Turbo%20Pascal/tp4_compi...
(3) https://dosdays.co.uk/media/borland/Turbo%20Pascal/tp302_edi...
(4) https://www.smoliva.blog/img/cc-pathminder.png
(5) https://winworldpc.com/res/img/screenshots/IBM%20FileCommand...
https://www.scribd.com/document/693329404/IBM-SAA-CUA-Basic-...
https://www.scribd.com/document/691545759/IBM-Object-Oriente...