Not to mention that the article author apparently likes dark-on-light coloration (“light mode”), whereas I like light-on-dark (“dark mode”).

Traditionally, most computers were light-on-dark. I think that was the Mac that really shifted things to dark-on-light.

My understanding from past reading was that that was because of the observation that people were generally working with computer representations of paper documents, which for ink economy reasons (ink costs something, so normally you’d rather put ink on 5% of the page rather than 95% of the page) were normally dark-on-light. If you had a computer showing a light-on-dark image of a document that would be dark-on-light on paper, that’d really break the WYSIWYG paradigm. So word processors and the like drove that decision to move to dark-on-light:

Technically, I suppose it wasn’t the Mac where that originated, just where it was popularized. The Apple II had some kind of optional graphical environment that looked like a proto-Mac environment, though I rarely saw it used:

The Mac derived from the Lisa at Apple (which never became very widespread):

And that derived from the Xerox Alto:

But for practical purposes, I think that it’s reasonably fair to say that the Mac was really what spread dark-on-light. Then Windows picked up the convention, and it was really firmly entrenched:

Prior to that, MS-DOS was normally light-on-dark (with the basic command line environment being white-on-black, though with some apps following a convention of light on blue):

Apple ProDOS, widely used on Apple computers prior to the Mac, was light-on-dark:

The same was true of other early text-based PC environments, like the Commodore 64:

When I used VAX/VMS, it was normally off a VT terminal that would have been light-on-dark, normally green, amber, or white on black:

And as far as I can recall, most terminals for Unix were light-on-dark.

If you go all the way back before video terminals to teleprinter, those were going back to paper, so the ink issue comes up again, and they were dark-on-light:

But I think that there’s a pretty good argument that absent ink economy constraints, the historical preference has been to be light-on-dark on video displays.

There’s also some argument that for OLED displays – and, one assumes, any future displays, where you only light up what needs to be light, rather than the LCD approach of lighting the whole thing up and then blocking and converting to heat what you don’t want to be light – draw somewhat less power for light-on-dark, which provides some battery benefits, though in most cases, that’s probably not a huge issue compared to eye comfort.