comment variables

https://www.gravatar.com/implement.php#section_2_2
or / and
https://www.ads-software.com/support/10/10300

and
https://www.scriptygoddess.com/archives/2004/06/21/comment-highlighting-based-on-author/

Try putting this inside your comment loop:
<?php var_dump($comment); ?>
It’ll tell you all the variables that are available in the comment loop for you to use.

Thanks, i wrote my own function in template-functions-comment.php, smth like this:

function authorclass() {
global $comment;
$author = apply_filters('comment_author', $comment->comment_author);
if (!$author) $author = 'Anonymous';
if ($author=="akella") :
echo "\"class=akella\"";
else:
echo "";
endif;
}