The Block Styles in PublishPress Blocks are very useful for designing your WordPress site. However, some CSS properties could mess up the Gutenberg admin layout. So not all custom styled applied in the WordPress admin.
To help you use the custom styles for heading, list, code, preformatted, table, columns and group blocks, we've added a color to identify the style. In the image below, the blue color for this style is shown in the admin area.