I'm a new user. I was looking at the main site, and trying to learn more about how things work, so I clicked the FAQ link; then I clicked something else, I'm not sure what, and found a bunch of interesting questions about meta topics. After ten minutes of clicking around and reading questions, I clicked the FAQ link again, and only then discovered that I'm now on the meta site.
I see now that the color schemes are different, but I never would have noticed that. (I'm partly color-blind.) I also see now that the word "meta" appears in the banner at the top of the page--but I had looked at that banner half a dozen times before I saw that word; it's small and squeezed close to "USAGE".
So I'm wondering if there could be clearer signposts for people entering the meta site. A notice saying "You are now entering THE METAZONE"? A bigger or more separated "meta" label at the top (perhaps on a line by itself underneath the title)? A stronger color difference? I dunno; I'm not a designer. But it would've been helpful to me to have a stronger differentiation.
That said, this may only be an issue for the few new color-blind users who accidentally stumble across the meta site; and even then, it's not a huge problem. So this may not be worth improving; just a thought.