since I'm trying to answer.....I'm not off topic....oops.

It looks to me like it does have to do with whether the person is newer of older (actually the # of posts) on PC. It looks like the lower # of posts or the more new members have their names in black. Then after a certain higher # (which I have no idea what that is) the name changes to blue.

It looks like Moderators are green, Admin is red?

just guessing, but that looks like the patern I see,
Debbie