I switched to the "scraplight" theme, took a look around, then switched back to "scrapdark". The usernames that were black are now white. If nobody made any server-side changes, then I suppose that must have refreshed the Web site's CSS for my profile.
I tried the same thing at work, and the affected user names are still black. At home, I'm on a PC using FireFox, at work, I'm on a MacBook Pro and Safari. I have a PC at work too, maybe I'll try the theme swap on it.
