What?

Revert block_core_navigation_submenu_build_css_colors().

Why?

As reported in WordPress trac https://core.trac.wordpress.org/ticket/58670, remove block_core_navigation_submenu_build_css_colors() function without any deprecation can probably trigger a PHP Fatal error when we update to WordPress 6.3 and a third-party plugins as ours use this function.

The block_core_navigation_submenu_build_css_colors() function was removed in https:/github.com//pull/48936 and doc block in #52152

How?

• Revert both of the block_core_navigation_submenu_build_css_colors()
• Add a deprecation to warn developers that this function will be removed in a future release as suggested in Navigation Link: Don't remove 'block_core_navigation_link_build_css_colors' #49064

Step-by-step reproduction instructions

For example we use this function in one of our block which is a child of the core/navigation block

$colors      = block_core_navigation_submenu_build_css_colors( $context, $attributes, $has_submenu );
$classes     = array_merge(
	array( 'wp-block-navigation__submenu-container' ),
	$colors['class']
);
$css_classes = trim( implode( ' ', $classes ) );

to be able to get the style from the context of the core/navigation block.

Screenshots, screen recording, code snippet

No response

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.

No