Auto color any admin replies

Is it possible to automatically have any replies by admin be colored so we don’t need to manually do it every time? Also can we add some kind of Admin label or badge to the posts so people know?

I’ve do that in CSS:

    span.username.moderator a, span.username.moderator i {
    color: green;

span.username.admin a, span.username.admin i {
    color: #A40000;

Color username in red if you are admin or in green if you are moderator.
Live example here: (Normal user then administrator then moderator)