Administration: Update dashboard welcome panel colors, remove broken link

Remove the green background from the "dot" accent, to prevent low contrast for the dismiss button. Use menu colors for the background on alternate color schemes. Remove the "Edit styles" link as there is no longer a direct link to the global styles section of the site editor.

Follow-up to [55451].

Props sabernhardt, ryokuhi, laurlittle, richtabor.
Fixes #57759.


Built from https://develop.svn.wordpress.org/trunk@55574


git-svn-id: http://core.svn.wordpress.org/trunk@55086 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/includes/dashboard.php

@@ -2095,7 +2095,6 @@ function wp_welcome_panel() {
 			<?php if ( $is_block_theme ) : ?>
 				<h3><?php _e( 'Switch up your site&#8217;s look & feel with Styles' ); ?></h3>
 				<p><?php _e( 'Tweak your site, or give it a whole new look! Get creative &#8212; how about a new color palette or font?' ); ?></p>
-				<a href="<?php echo esc_url( admin_url( 'site-editor.php?styles=open' ) ); ?>"><?php _e( 'Edit styles' ); ?></a>
 			<?php else : ?>
 				<h3><?php _e( 'Discover a new way to build your site.' ); ?></h3>
 				<p><?php _e( 'There is a new kind of WordPress theme, called a block theme, that lets you build the site you&#8217;ve always wanted &#8212; with blocks and styles.' ); ?></p>