Fix $theme-color CSS variable in template-part/editor

[ItsJonQ]

This update fixes the node-sass build with the reference to$theme-color. This variable isn't defined, which causes an error in the build. It was replaced with $blue-wordpress-700.

Note: I'm not too sure what $theme-color may be. I used my best guess and picked the "theme" colour used in the Gutenberg editor.

How has this been tested?

Local Gutenberg.

• Run npm run dev
• Webpack should build without issues
• Make sure local Gutenberg editor styles look ok 👍

Checklist:

• My code is tested.
• My code follows the WordPress code style.
• My code follows the accessibility standards.
• My code has proper inline documentation.
• I've included developer documentation if appropriate.
• I've updated all React Native files affected by any refactorings/renamings in this PR.

Fixes: #23217

[noahtallen]

@ItsJonQ is there a variable which is based on the "color scheme" (I know it's possible to set your own primary colors and whatnot)? That could be considered a "theme", I guess.

[ItsJonQ]

@ItsJonQ is there a variable which is based on the "color scheme" (I know it's possible to set your own primary colors and whatnot)? That could be considered a "theme", I guess.

I don't think we have a SCSS variable in the editor.
Looking through the code, it looks like there's a CSS variable that's being used:

var(--wp-admin-theme-color)

I can't confirm, as I haven't worked with these variables yet. But it looks like it's the closest one

It looks like Travis is unhappy with another issue 😅

[epiqueras]

Why was the variable removed?

The value came from the theme values in packages/base-styles/index.js which get injected with @wordpress/postcss-themes I think.

[ItsJonQ]

@epiqueras Hmm! I wasn't aware of the PostCSS plugin.

I just raised the issue + PR because I noticed recent builds + npm run dev failing due to this particular variable.

[epiqueras]

Maybe they were swapped for CSS variables?

[epiqueras]

cc @nosolosw @gziolo

[epiqueras]

Yeah, they were. Closing in favor of #23221.