Default/core color palette unavailable with block themes

[Andrew-Starr]

Describe the bug:

With a block theme (full site editing), the theme can define whether the default/core colors are available in the editor. e.g. in theme.json -> settings.color.defaultPalette can be true or false, and the theme can additionally define its own color palette.

The issue is that the CoBlocks blocks only have the theme colors available for use. This contrasts with core blocks that respect the theme choice and will have the default colors available if not removed by the theme.

This is particularly jarring when using the Accordion block, with the accordion item title only having access to the theme colors, and the content (core paragraph block) of the same accordion item having access to both the theme colors and the default/core colors.

To reproduce:

1. Activate a block/fse theme that does not remove the default color palette, or edit theme.json to set settings.color.defaultPalette to true
2. Add or edit a page/post and add any CoBlocks block that has color support e.g. Accordion or Icon
3. Select text color or background color for the block
4. Notice how only the theme color palette is available, and the default/core colors are missing
5. Add a core block, or change the color of the content area of an Accordion item and notice that both the theme colors and the default colors are available

Expected behavior:

Default/core colors should be available for selection in all applicable blocks.

Screenshots:

Isolating the problem:

• [ x] This bug happens with no other plugins activated
• [ x] This bug happens with a default WordPress theme active
• [x ] This bug happens without the Gutenberg plugin active
• [x ] I can reproduce this bug consistently using the steps above

WordPress version:

5.9.2

Gutenberg version:

N/A