One-click theme packs are coming to Android thanks to Google’s new Theme Manager

Pixel phones haven’t traditionally been known for providing extensive customization options, but that perception is changing as Google adds new home and lock screen personalization features in the latest version of Android. The introduction of Material 3 Expressive in the first quarterly release of Android 16 has dramatically overhauled the look and feel of Android on Pixel phones, bringing a fresh, more vibrant experience across the board.

Still, Pixel phones lag behind some of their competitors in ease of customization. While many rival devices let you change the entire look and feel of the UI with single-click custom themes, Pixel phones lack this convenience, requiring you to manually configure the home and lock screens to achieve your desired look.

Fortunately, that could change in the near future. Back in May, we revealed that Google is working on theme packs to help you customize your Pixel phone. We surfaced a new “Themes” entry in the “Wallpaper & Style” app on Pixel phones, and while it wasn’t functional, its description provided some crucial information. Our discovery confirmed that Google is working on “Pixel themes” consisting of multiple customization options bundled in packs, but details were scarce at the time.

In recent weeks, however, we’ve learned more about how the Pixel themes feature will work. Specifically, we found evidence in the Android 16 QPR2 betas that Google is developing a new system feature called Theme Manager. This provides the foundation for Pixel themes by improving how system themes are handled in Android. Here’s how.

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How Google is evolving theming support in Android

Before this year, the last time Google overhauled Android’s UI was in 2021 with the release of Android 12, which introduced the original version of Material Design 3, also known as Material You. The centerpiece of Material You was “dynamic color,” a theming engine that automatically extracts colors from your wallpaper and applies them across the entire user interface — from the Quick Settings and volume panel to compatible third-party apps.

The process that Material You follows to generate a theme can be broken down into three parts:

1. Extracting colors. When you apply a wallpaper, Android analyzes it to determine the dominant color. This color is used as a “seed” from which five unique tonal palettes (three accents and two neutrals) are generated. Each of these palettes contains 13 colors of different luminance values.
2. Applying colors. Android then replaces the system color values that apps read from with these 65 new colors. It does this by generating Runtime Resource Overlays (RROs), which allow Android to replace resource values on the fly without rebooting the device.
3. Storing preferences. Finally, Android stores the user’s theme preferences. This includes the source of the seed color (the lock screen wallpaper, home screen wallpaper, or a preset), the theme style (which variation of the dynamic color algorithm was used), and the time the theme was applied.

While this process works on the surface, Google seems to believe that the way Android currently stores the user’s theme preferences is outdated. Right now, the user’s entire theming configuration is stored as a raw block of JSON in the THEME_CUSTOMIZATION_OVERLAY_PACKAGES secure setting. Every time the system needs to change the theme — for example, when the user changes their wallpaper — it has to read the entire text block, modify only the relevant parts, and then write it back.

The issue with this approach is that it’s brittle. If a modification corrupts the text block, it could cause the theme to break or, worse, SystemUI to crash. Furthermore, the lack of a central authority managing theme changes can lead to conflicts when multiple apps try to make modifications simultaneously. While only privileged apps can access and modify the configuration, the WRITE_SECURE_SETTINGS permission they need to hold is overly broad, providing access to more than just the theme configuration. As Google expands Android’s theming options and introduces more apps that can modify the system theme, it has become necessary to modernize the theming architecture.

This is likely why Google created the new Theme Manager API, a complete architectural overhaul of Android’s theming system. It solves many of the aforementioned problems by moving to a formalized, service-oriented architecture. Instead of manipulating the raw theme configuration text, apps now hand a structured object to the Theme Manager, which acts as the central gatekeeper, validating, storing, and applying the theme.

Under this new system, only apps with the UPDATE_THEME_SETTINGS permission can change the system theme. This permission is restricted to apps signed with the platform certificate, making it both less accessible and less broad than the previous permission.

So, what does Theme Manager mean for Pixel themes? It boils down to how the new API facilitates preset theme management. While the old system focused on dynamic color extraction from user-supplied wallpapers, the new system expands on this by making it easier for apps to supply predefined theme settings, i.e., theme packs. Google’s new customization app, for example, can use the new ThemeSettingsPreset class to send explicit system and accent colors defined by a theme pack.

While Pixel theme packs will likely encompass more than just predefined wallpapers and colors, the new Theme Manager API is a crucial part of Google’s efforts to expand theming support on Android. We’re excited to see what Google’s designers create for Pixel users, and hopefully, we won’t have to wait too long to try them out. Since the Theme Manager API isn’t public, there’s nothing stopping Google from shipping Pixel themes in Android 16 QPR2, which will be released months before next year’s Android 17 update.

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