Color Randomizer – does not work with no colors in theme.json

[colorful-tones]

Description

When using the Create Block Theme plugin to generate a blank theme, no colors are available in the blank theme's theme.json. Therefore, when you go to use the Color Randomizer, it throws an error in the console:

react-dom.min.js?ver=18:1 Uncaught TypeError: Cannot read properties of undefined (reading 'map')

Step-by-step reproduction instructions

1. Activate Gutenberg and Create Block Theme plugin
2. Be sure to go to Gutenberg > Experiments and activate the Color randomizer experiment.
3. Visit Appearance > Create Block Theme (WP Admin)
4. Choose 'Create a blank theme' and Save
5. Visit Appearance > Themes, and activate the newly created blank theme
6. Visit Global Styles > Colors in Appearance > Editor and hit the 'Randomize colors` (open browser console for error)

Note: after creating a blank theme you can deactivate the Create Block Theme plugin and the issue still persists.

Screenshots, screen recording, code snippet

No response

Environment info

WordPress 6.2
Gutenberg 15.6.2
Create Block Theme plugin 1.8.2

Please confirm that you have searched existing issues in the repo.

Yes

Please confirm that you have tested with all plugins deactivated except Gutenberg.

Yes