it's already available for you..
FIND in postbit template:
HTML Code:
<if condition="$show['moderated']">
<td class="alt2" id="td_post_$post[postid]">
<else />
<td class="alt1" id="td_post_$post[postid]">
</if>
REPLACE with:
HTML Code:
<if condition="$show['moderated']">
<td class="ADD_NEW_CLASS" id="td_post_$post[postid]">
<else />
<td class="alt1" id="td_post_$post[postid]">
</if>
replace ADD_NEW_CLASS with your own class