To add to @Mittineague, here’s what I generally do:
Normally, I just post. I don’t really worry whether I’m seen as a mod or not - but that might just be the atmosphere in our community.
If I need to say something as a “regular user”, ensuring that my comment is not construed to be official, I add a disclaimer at the bottom. Something like: Note: this is my personal opinion, I’m not speaking in my role as a moderator.
Conversely, when I need to be sure that my comment is understood to be official, I use staff color.