You don’t have to wait until the finished release of Android 12 to know how it will affect your apps. XDA and tipster Pan Du report that Google has updated Messages with preliminary support for Android 12’s Material You design.
Enable the feature on a device running the Android 12 beta and the new Messages (8.2.042) will add variants on your theme color to multiple interface elements, including the search bar, category tabs when available, and the floating action button. If you have a colorful wallpaper, then, your text chats should be just as vibrant.
See also: The best chat and messenger apps for Android
The Android 12-oriented feature isn’t currently available in the Messages beta, and doesn’t necessarily affect all elements of the app.
You’ll have to wait until the wider release of Android 12 (likely in late summer) before this update becomes commonplace. It may also take a while for Gmail and other apps to properly support color theming. At present, though, the release offers a hint at what Android 12 will look like once many of your apps support Material You — like it or not, your phone is about to color-coordinate.