Board Thread:Support Requests - Getting Technical/@comment-27059263-20170226080040/@comment-9605025-20170226175821

Modifying KockaAdmiralac's response, I believe the following should accomplish the desired task for both the rail and the icon in the upper right corner.

Edit:

Since the badge in the upper right corner is seen only by the chat moderator, you could also just have each chat moderator add the following to his/her personal chat CSS. Then, the site-wide chat CSS would simply be the following.