With Android 12, Google introduced the world to Material You and the wonders of dynamic theming. Its ever-changing UI grabbed its colors based on whatever wallpaper you had on your phone, and we absolutely loved it. The only problem was that the actual color-picking engine used on Pixel phones wasn't open source, leaving smartphone OEMs to recreate their own versions if they wanted to support dynamic theming for their Android 12 phones. Now that's no longer necessary, as Google's "monet" palette generation code goes open-source with the release of Android 12L.

We've been expecting this for months now, back before we even knew 12L was going to be a thing — preparation was underway to bring that code to the AOSP sometime after the initial release of 12. Right on cue, just as the newest version of the operating system makes its way to Pixel phones around the world, the previously closed theming system is now open source.

This means smartphone makers who want to support dynamic theming with their respective Android 12L updates can now do so using monet instead of recreating things with their own system, as companies like Samsung have done. Whether they use choose to use monet or not, they're going to have to do something, at least — Google shared last month that dynamic theming was headed to more and more phones, and from what we were told, it's going to become mandatory for GMS-certified devices at some point.

This also means custom ROMs based on Android 12L will almost definitely support dynamic theming. The few 12-based ROMs that have it already basically just do the same thing as Samsung — make an almost-identical system to draw colors from your wallpaper and apply them to UI elements. All told, this is some good news for the open-source community, but probably not too impactful for most people, as OEMs were already supporting dynamic theming without monet anyway.