While functional improvements for MBS almost certainly take precedence over this ticket, I think it would be quite nice if the MB UI had a "dark mode" theme baked in as an alternative to the default theme. The default theme uses a lot of white backgrounds and black (or similarly dark) text, which can worsen eyestrain at night, throw off circadian rhythms, etc. (Some users may also simply have an aesthetic preference for "dark mode" themes.)

Although some editors have created userscripts or custom styles that users can apply in their browsers, and there are browser extensions out there (e.g., Dark Reader) that can attempt to force "dark mode"-like style changes, in my experience these can have a significant negative impact on performance while editing, and I'd like to think this wouldn't be a particularly difficult UI change to implement, even pending any major redesigns of the MB UI.

As for how to implement this, one method might be to simply respect system- or browser-asserted dark mode via the CSS prefers-color-scheme query and select different color palettes for presentation to the user depending on the result of the query. Another option might be to add a footer toggle that creates/manages a cookie, or perhaps a user preference option (which would have the benefit of applying the theme regardless of which device the user is logged into MB with), but I suspect that simply respecting client-asserted theme preferences might be the most straightforward path to checking & responding to user choices for light/dark mode.