Google has been shying away from integrating a dark theme in it’s recent AMOLED Nexus and Pixel phones, despite a lot of interest from consumers. Unlike LCD, OLED technology doesn’t rely on a backlight to illuminate pixels, allowing black areas of a screen to be truly black as each individual pixel illuminates itself. This means that dark wallpapers and pages will save battery life because only the illuminated parts of the screen are drawing power. And dark themes just look cooler. XDA has been digging through the new Pixel 2’s software and actually found an unmentioned, disabled dark theme.
What XDA found was a dark theme app (named “Dark”) that was impossible to access without an Android Debug Bridge (ADB), which they couldn’t try on Verizon display models. The app’s package name is “com.android.systemui.theme.dark” and is stored in “/vendor/overlay/SysuiDarkTheme/SusuiDarkThemeOverlay.apk.” They also discovered that Android 8.0 Oreo has integrated support for themes, similar to what Sony, Samsung, HTC and others have within their modified skin overlays. With a little work, it’s possible to install a dark theme on a stock Android 8.0 Oreo device without rooting.
The dark theme above was installed using the Andromeda add-on for Substratum, which was developed by XDA and Substratum to allow theme support without root. It’s not a simple method and requires a Windows, Mac or Linux computer, but it’s easy enough for enthusiasts to accomplish without much of a fuss.
XDA figured out that the dark theme APK in Android 8.0 Oreo is an OMS (Overlay Manager Service) theme for system UI, based on where it’s stored. They found it in the directory that Google has other vendors put themes that they want pre-installed, implying that stock Oreo has baked in compatibility for custom themes.
According to The Verge, the dark theme isn’t entirely disabled. For example, if you use a dark wallpaper, the notification shade and app launcher will also become dark automatically to match. To add to the confusion, ArsTechnica claims that the dark theme only controls the quick settings panel. XDA even found some code that confirms the darkening of that panel. They also couldn’t replicate The Verge’s claims about the darkening of the notification shade and app launcher as nothing changed when they used a dark wallpaper on Verizon display units.
At the end of the day, this is what we’re left with. There isn’t a simple switch in Android 8.0 Oreo’s settings that will enable a dark theme. It’s possible that dark wallpapers could trigger some changes, but that’s entirely unclear at this point. What we have is some hidden code that technically allows for a dark theme, but future updates from Google are necessary before the average user will have access to custom themes on stock Android 8.0 Oreo.