I would, however, assume that given that there's bleed (or maybe it's "bloom"?  IDK) on a CRT, light-on-dark is more readable.

I think Dark Mode is just because the kids these days have become troglodytes whose only interaction with other beings is mediated through their screens, and they keep themselves in the dark because the light, it burns us, it burns us, my precioussss.

At least I no longer have to worry about them getting off my lawn.

On Thu, Jun 15, 2023 at 6:25 PM Warner Losh <imp@bsdimp.com> wrote:


On Thu, Jun 15, 2023, 2:56 PM segaloco via COFF <coff@tuhs.org> wrote:
Good afternoon everyone. I've been thinking about the color/contrast landscape of computing today and have a bit of a nebulous quandary that I wonder if anyone would have some insight on.

So terminals, they started as typewriters with extra steps, a white piece of paper on a reel being stamped with dark ink to provide feedback from the machine. When video terminals hit the market, the display was a black screen with white, orange, green, or whatever other color of phosphor they bothered to smear on the surface of the tube. Presumably this display style was chosen as on a CRT, you're only lighting phosphor where there is actually an image, unlike the LCD screens of today. So there was a complete contrast shift from dark letters on white paper to light letters on an otherwise unlit pane of glass.

Many terminal had a reverse video setting even in advance of the graphical interfaces

Step forward to graphical systems and windows on the Alto? Light background with dark text.
Windows on the Macintosh? Light background with dark text.
Windows on MS Windows? Light backgrounds with dark text.
Default HTML rendering in browsers? Light backgrounds with dark text.

You can add x10/x11 to the early list... as well as decwindows on the VAX station ii era...

Fast forward to today, and it seems that dark themes are all the rage, light characters on an otherwise dark background. This would've made so much sense during the CRT era as every part of the screen representing a black pixel is getting no drawing, but when CRTs were king, the predominant visual style was dark on light, like a piece of paper, rather than light on dark, like a video terminal. Now in the day and age of LCDs, where every pixel is on regardless, now we're finally flipping the script and putting light characters on dark backgrounds, long after any hardware benefit (that I'm aware of) would be attained by minimizing the amount of "lit surface" on the screen.

Anyone know if this has all been coincidental or if the decision for graphical user interfaces and such to predominantly use white/light colors for backgrounds was a relatively intentional measure around the industry? Or is it really just that that's how Xerox's system looked and it was all domino effect after that? At the end of the day I'm really just finding myself puzzling why computing jumped into the minimalism seen on terminal screens, keeping from driving CRTs super hard but then when GUIs first started appearing, they didn't just organically align with what was the most efficient for a CRT. I recognize this is based largely in subjective views of how something should look too, so not really expecting a "Person XYZ authoritatively decided on <date> that GUI elements shall overwhelmingly only be dark on light", just some thoughts on how we got going down this path with color schemes in computing. Thanks all!

Dark on light was to mimic paper.

I'm also skeptical that light on dark uses less power or was easier to implement except maybe in the very earliest vector displays...

Warner

- Matt G.