Nested Submenu block not rendering submenu/overlay colours on the front end

[tellthemachines]

Description

If a custom or theme submenu/overlay colour is set on the Navigation block, any Submenu block it contains won't inherit those styles on the front end, because the colour classnames and inline styles aren't rendered in the block. In the editor the colours appear correctly.

Step-by-step reproduction instructions

1. In a Navigation block, set Submenu & overlay text and background colours to other than default value.
2. Add a Submenu block to the Navigation, and add another Submenu inside the Submenu.
3. Save, and verify that while in the editor the colours appear correct, in the front end the nested Submenu colours are still the default ones.

Screenshots, screen recording, code snippet

The submenu li doesn't have the same classnames as the navigation link li:

Environment info

No response

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