I tried, but I just can’t believe anything written after that statement. The default was white (or green or orange) on black.
All these white backgrounds are fairly new - probably there are more years with white than black backgrounds, but that’s not how my old brain think of time.
The vast majority of the world's population have rarely or never used a monochrome computer screen. Even when they were common, the bulk of what people read, _even people who used such monitors_, was black on white - it was paper.
In the Unix world it became common with the introduction of the X Window System.
In the personal computer world it also became common with the launch of Microsoft Windows 1.0 and Apple Macintosh.
Mac was always a tiny fraction of the market. No one used Windows 1.0. High end UNIX workstations were extremely rare.
What was common was DOS, the other home micros, and dumb terminals. All black background.