One of the marquee features that Apple showed off for macOS Mojave at WWDC is Dark Mode. As the company demonstrated during the WWDC keynote, Dark Mode is a far more ambitious feature than the dark theme added to macOS Yosemite in 2014. The new look extends much deeper into the system affecting everything from app chrome to window shadows and Desktop Tinting.
There is a lot more to Dark Mode than you might assume. To help developers navigate when and how to implement Dark Mode, Apple has provided developers with guidelines, which Stephen Hackett covers on 512 Pixels:
The biggest is that not all apps should always follow the Appearance that has been set by the user. As before, Apple believes that media-focused tools should be dark at all times. I don’t foresee something like Final Cut Pro X gaining a light theme anytime soon.
Apple has also given developers the ability to use the Light Appearance in sections of their applications. One example is Mail, which can use the Light Appearance for messages, but the Dark Appearance for its window chrome, matching the system[.] This lets text and attachments be viewed more easily for some users. I think it’s a nice nod to accessibility for text-heavy apps, and I hope third-party developers take advantage of this ability.
Hackett also covers Accents, an adaptation and expansion of what is currently called Appearances that affect the look of things like drop-down menus, and how Accessibility features affect Dark Mode.
I like the look of Dark Mode a lot and hope third-party developers adopt it quickly. I expect the pressure to add Dark Mode to existing apps will rapidly increase as more and more third parties begin to use it and hold-out apps become bright, glaring reminders among a sea of muted windows.