Navigation Block: Empty state isn't visible against dark background

[annezazu]

Description

The navigation block's default state isn't visible against a dark background.

Step-by-step reproduction instructions

Please list the steps needed to reproduce the bug. For example:

1. Open the site editor or a new page/post.
2. Add a cover block and set the background to a dark color like black.
3. Add a navigation block.
4. Select "Start Empty" and see that the default state is almost impossible to see.

Expected behaviour

I expected to be able to see the default state.

Actual behaviour

I'm unable to see the default, empty state.

Screenshots or screen recording (optional)

Screenshot:

Video:

empty.menu.mov

WordPress information

• WordPress version: 5.6.2
• Gutenberg version: 10.1
• Are all plugins except Gutenberg deactivated? Yes
• Are you using a default theme (e.g. Twenty Twenty-One)? TT1 Blocks