kingjeffrey

From the authors of <a href="https://wordpress.org/extend/plugins/wp-typography/" rel="ugc">wp-Typography</a> comes wp-AuthorComment, allowing you to uniquely style post author’s comments.
View the <a href="http://kingdesk.com/projects/wp-authorcomment/" title="wp-AuthorComment Homepage" rel="nofollow ugc">wp-AuthorComment homepage</a> for more information.

wp-AuthorComment

Uniquely style the post author's comments.

noel

“Per-post styles for new age art direction.”
Pay your respects to print, get Art Direction.
This plugin allows you to have global archive and single page per-post styles and scripts.
Need custom CSS everywhere? Try <a href="https://wordpress.org/extend/plugins/safecss/" rel="ugc">WordPress.com Custom CSS</a>
Notes: 
 * 0.2.4 Brings fixes for issues with caching plugins, support for localization, and the ability to put style-POSTID.css files in your template directory. 
 * As of 0.2.1, global and single page custom code are now inserted in the ! Valid code for everyone! 
 * 0.2 adds role checking and fixes a bug where duplicate global css can occur.

Art Direction

"Per-post styles for new age art direction."

wp-AuthorComment vs Art Direction