I had to make these for myself, so I decided I would post them. These are the same smilies I use on my forums, I just copied them over to the /components/com_comment/joscomment/emoticons directory and synchronized the existing default php file with these. They look the same as the default smilies, just dark backgrounds instead of white.

Hope this helps someone. Please let me know if there are problems or you need help! Preview:

Gamers Nexus - Dark Smilies Zip for CompojoomComment