The trick was found by Mishaal Rahman of XDA Developers while digging through the new Android 11 system files. The change is named “QSColorController” in the System UI and allowed Rahman to get his paint box out:
While some versions of Android such as Samsung’s One UI and Huawei’s EMUI allow for the changing of themes, and indeed of third party themes, Google’s version of Android on the Pixel line has remained far less customisable, only recently receiving a system wide dark theme.
With this colour changing discovery in the earliest build of Android 11, perhaps Google is considering letting users tinker far more with how their phone looks. It’s often a big draw for Android enthusiasts in the first place, so it only makes sense that Google keeps up with its OEM partners in letting Pixel owners skin their device’s software in the out-the-box settings.