More and more, the phone apps I use have adopted dark user interfaces, often with pure black backgrounds and dimmer whites. I’ve really come to love this! I often keep my brightness as low as possible, to save both my battery life and my eye balls, and these darker interfaces really look greater when the brightness is lower. Most of my apps added their dark UI because on OLED displays (which the fancy new iPhone adopted) pure black pixels are turned all the way off, which can further maximize battery life.
Beyond technical reasons, I also love the aesthetics of dark UI. Since the pixels turn off, the boundary between the edge of the screen and the body of the phone disappears—it blurs the line between hardware and software and is a very cool effect. It also references the historic tradition of computing. Developer applications like text editors and terminals usually default to dark interfaces, following user preferences and a long legacy of software development tools, going all the way back to the first digital displays. It was only when our graphical screens started to go WYSIWYG and simulating the look and feel of ink on paper that dark text on white backgrounds became the norm, continuing to today.
Dark interfaces are also more honest to the display hardware we use today. Screens emit light, rather than reflecting it, which means they have intrinsic properties totally separate from ink on paper. That’s why screens use RGB, an additive color model, rather than the subtractive CMYK color model that’s used in printing. Of course, this is the kind of detail that only people like publishing nerds really pay any attention to.
That’s not to say there’s no validity to dark text on light backgrounds, especially when accessibility is a concern. In my own, cursory research I found up a conclusion from Jason Harrison, Post Doctoral Fellow, Imager Lab Manager at the Sensory Perception and Interaction Research Group, University of British Columbia:
People with astigmatism (aproximately 50% of the population) find it harder to read white text on black than black text on white. Part of this has to do with light levels: with a bright display (white background) the iris closes a bit more, decreasing the effect of the “deformed” lens; with a dark display (black background) the iris opens to receive more light and the deformation of the lens creates a much fuzzier focus at the eye.
It’s important that people be able to read in the way that’s most comfortable for them! Whether it’s somebody with astigmatism who finds dark-on-light easier for them, or whether it’s me wanting as low a brightness as I can manage.
That’s part of the reason why, on Massive, I recently added a light switch to the menu bar. Partly, it was to test out my style cascade and experiment with more radical theming that we’ll be using for Reports and other features. But also, it’s because while I wanted us to default to a light-on-dark default that’s familiar to readers, I myself wanted the ability to turn the brightness off! I’ll probably copy that light switch over to this site at some point soon, too.
That being said, I’m really pleased that the cultural trend is starting to swing back from dark on light to light on dark. There’s always going to be WYSIWYG and the inefficiencies it introduces—we’ve got to design for users where they are rather than expect them to adapt to our arcane “best practices.” Even if nobody else cares, I’m at least glad I’m getting the option more and more, since I’ll take it every chance I get.