Currently in Android 11, there are two different theme options in stock Android. Light and dark modes. Which afford the user either a white or black background for things like the notification panel and the main settings menu.
Android 12 though seems to be in the early stages of what might be additional options for new system themes.
Android 12 could eventually introduce new options for system themes
While there is no guarantee that Google will add this, it does now seem more possible than before. Android Police points out that in the notification panel and in all settings menus save for the main top level settings screen, there is now a blue tint to the background.
This applies to both the light and dark modes. So no matter which theme you apply, there’s a slight hint of blue. Whether or not Google continues with this is unknown. Especially this early. Google for example may decide to remove this tint in a future developer preview release. Or in one of the betas that are to follow them.
There are no other tints that seem to appear other than blue. So if new theme options do come up later, blue may be the only one. Or maybe Google is just saving other options for later on when a full release is being pushed out.
Working with one new theme option compared to several does seem like it would be easier after all.
A previous leak suggests support for more theme colors
Prior to the release of Android 12 developer preview 1, a leak surfaced which showed some mock ups with the Android 12 design.
In those leaks, the system theme color didn’t look like it had a blue tint. Nor did it appear to have the same black or white design that themes currently display in Android 11. Instead everything from the notification panel to the settings to the toggles and home screen widgets had a more neutral earth tone.
Consisting of beige and light brown hues. This paired with the blue tint from today’s released preview, is a decent indicator that more theme options are on the way. Worth keeping in mind is that the leak is just that. A leak. New theme options do seem a bit overdue though.