Here is the code;

We will edit your WordPress’ theme. You should make a backup of comments.php. If you make a backup, continue…

We will edit comments.php and we add some code into this file. First, look at the code;

<ol id="commentlist">

<?php $i = 1; ?>
<?php foreach ($comments as $comment) : ?>
<li <?php comment_class(); ?> id="comment-<?php comment_ID() ?>">
<?php echo get_avatar( $comment, 32 ); ?>
<?php comment_text() ?>

<p><cite><?php comment_type(_c('Comment|noun'), __('Trackback'), __('Pingback')); ?> <?php _e('by'); ?> <?php comment_author_link() ?> &#8212; <?php comment_date() ?> @ <a href="#comment-<?php comment_ID() ?>"><?php comment_time() ?></a></cite> <?php edit_comment_link(__("Edit This"), ' |'); ?></p>
<div class="commentnumber">#<?php echo $i; ?></div>
</li>
<?php $i++; ?>

<?php endforeach; ?>

Do you see the added code? If you don’t i will write them here. Add this codes into your comments.php like me;

<?php $i = 1; ?>
<div class="commentnumber">#<?php echo $i; ?></div>
<?php $i++; ?>

If you want to add link to reply. Just change  #<?php echo $i; ?> with this code;

<a href="#comment-<?php comment_ID() ?>" title="">#<?php echo $i; ?></a>

Finally, The CSS. Add this css into your style.css;

/* Comment Numbers */
.commentnumber {
position: absolute;
right: 5px;
top: 5px;
font-size: 18px;
color: #454545;
}
.commentlist li {
position: relative;
}
/* Comment Numbers */

That’s All. This is the screenshot :)

Here is the code;

First one in comments.php file. Find this code;

<li <?php echo $oddcomment; ?>id="comment-<?php comment_ID() ?>">

And change with this one;

<li class="<?php if ($comment->user_id == 1) $oddcomment = "authorstyle"; echo $oddcomment; ?>"

After that open your style.css file and add this lines in to it;

.authorstyle {
background-color: #B3FFCC !important;
} 

That’s All. Have a nice day!

Here is the code;

We will change our theme’s comments.php. First make a backup please. After bakcup you can add this code into your php file where you want to show this usable tags.

Usable XHTML Tags: <?php echo allowed_tags(); ?>

That’s All. Have a nice day!