Allow users to create notebook themes

[tom]

Sorry, I should have updated this thread: see

Feature unannouncement: dark mode

We just pushed a change that will affect a small set of users who have enabled Dark Mode: in particular, Dark Mode’s going away. Alas, we couldn’t find a nice middle that would confer the eye-saving benefits of editing on a dark background, but not place new requirements on notebook authors - like the need to design dark charts. We want Observable to be flexible and feel like a well-honed tool, but sometimes those things are in conflict - so in this case we want to devote time to making the def…

In short, we removed dark mode because it made life harder for notebook authors.