Wordpress - How to highlight blocks borders in Gutenberg

A lot of people hate the Gutenberg editor because it is difficult to edit in, but there is a trick that allows to edit comfortably. It is a piece of code that adds borders to blocks and paragraphs, which needs to be inserted in functions.php:

add_action( 'admin_head', function () { ?>
<style>
.block-editor-block-list__layout div.block-editor-block-list__layout
{	border:1px solid blue;
}
.block-editor-block-list__layout p
{	border:1px solid red;
}
.block-editor-block-list__layout div.block-list-appender
{	border:1px solid lime;
}
.block-editor-block-list__layout div.components-resizable-box__container
{	border:1px solid pink;
}
</style>
<?php } );

This code consists in a hook which will result in the editor looking like this. Red borders for paragraphs, blue borders for blocks and green borders for blocks that you can add:

Of course, you can change the colors if you wish.