Add a way to declare a custom color palette in Gutenberg

[melchoyce]

There's no way to overwrite the default color palette in Gutenberg on a WordCamp site. Can we find a way to allow this? Would make it much easier for designers and content creators to coordinate.

[coreymckrill]

In today's bug scrub, we discussed adding a WordCamp settings sidebar to the block editor UI where a custom color palette (and perhaps other things like in #4389) could be defined by the organizers. Similar to @ryelle's comment ​here.

[ryelle]

I have a prototype for this, after WCEU I can clean it up. I tried the gutenberg sidebar way first, but unfortunately the way GB sets up the colors means that we can't seamlessly update without a page reload (because GB reads the colors from a variable set on the page) - you can see this almost working ​on the prototype (not a stable prototype, and if you download it you'll need to npm install and npm run build to test it), but the colors reset when you update/publish a post.

The other direction I started going was the options page, so you set up your colors in a new page, then they're set as the editor colors when the editor initializes. ​There's an even less finished prototype here.

[dd32]

This ticket has been moved to GitHub ​https://github.com/WordPress/wordcamp.org/issues/624