Add new color variables to built-in non-tumblr palettes

[marcustyphoon]

Description

The new Tumblr design system has a new (huge) set of theme color variables, which Palettes for Tumblr doesn't currently override (see #191). Still not sure what we want to do about user-generated palettes re: these new colors, as it seems impractical to ask palette authors to manually pick all of them (particularly when, from the outside, we have no clue what any of them are for).

I assume the vast majority of extension users are using it for the three built-in non-tumblr palettes, though, and for those we only have to do this once. This thus just becomes a simple matter of manually picking 500 colors. Easy, no big deal. This PR is the result of doing this.

Just kidding. I used generative AI.

Just kidding again. I reverse-engineered a close approximation of the algorithm used to generate every new color key in the native true blue palette based on the original palette colors, then applied that to our three non-tumblr palettes (this involved using the https://github.com/color-js/color.js interpolation feature in srgb mode). Only the pink colors required some manual touch-ups, since for whatever reason the "pink" color in these palettes is grey; I don't actually know if this is a bug?

I don't have a demo UI, per se, but here's a screenshot of my dev UI with the real true blue, simulated true blue, 2016, 2013, and decision palette colors rendered:

Testing steps

Select one of the built-in non-tumblr palettes and confirm that elements such as the create button and notification badges are themed correctly. Confirm that elements are themed correctly on recently created pages that use the new theme color variables such as:

• https://www.tumblr.com/search/xkit/communities
• https://www.tumblr.com/communities/test-community-46174/settings
• https://www.tumblr.com/communities/communities-feedback/about

One can press shift-P repeatedly to cycle the selected Tumblr palette; in an ideal world this would have no visual effect on any of these pages when an updated extension palette is selected. This isn't actually the case, since some components (premium perks button, a selected community in the sidebar, the text below the new post bar, etc) are coded with DOM changes based on the currently selected palette, but there should be fewer of these changes with this PR.

[marcustyphoon]

Note, of course, that just because this follows the pattern used by the true blue, that doesn't make that pattern perfect. The post create button's hover color is created by blending 20% white into its non-hovered color; this in my opinion doesn't look good in our palettes, but it's at least reasonable. We could manually tweak these further.

[AprilSylph]

Only the pink colors required some manual touch-ups, since for whatever reason the "pink" color in these palettes is grey; I don't actually know if this is a bug?

Not a bug. The colour for the Video post type was previously grey; the 2018^[?] recolour that necessitated the creation of Old Blue changed it to pink.

[marcustyphoon]

Ah right—so whether the nostalgia palettes should make those variables pink or grey depends upon whether they get used in association with the video post type or in an unrelated circumstance, huh. (And I suppose that if they get used in both cases where one applies and cases where the other applies, there could be an inconsistency resolved only by changing the video color to pink.)

Too bad I don't have css sourcemaps! (From what I did look through, I don't think the pink colors are referenced anywhere.)

[marcustyphoon]

Just noticed that Decision is supposed to have a red accent color, not blue. Updating my algorithm to reflect this.

Edit: I changed "unread-tint" and "chrome-ui" to red. Kind of guessing, here.

[AprilSylph]

I see nothing immediately wrong with any of these 👍

[marcustyphoon]

Oops: I probably should have been more specific that the two PRs which use a separate data file for the new data entries (#216, #217) are kind of an alternative to this, which inserted the new data into the current file. Well—the decision about whether to use a new file or insert into the current one and the decision about whether to hardcode the Old Blue data and whether to use color-mix for it are separate ones, I guess, and I didn't PR all four combinations of each, I guess, is more specific.