Bad coolant seal or running rich?
 

So I bought a 1993 RX-7 Touring a couple weeks ago and I started to notice a small amount of thin white smoke coming out of the exhaust on a cold start up. It disappears after a minute or so. The engine has about 30k miles on it with a streetport and the previous owner had it tuned to be running rich. However, the smoke has a smell that I cannot identify if it is the smell of fuel or coolant. I've read other posts that have had the same issue but I can't find a definite answer. Any ideas?

You're not saying what part of the country you're in. But rotary exhaust is hot. Even hotter than the average piston engine. If it's cool enough in the morning, even this time of year, I've seen a bit of steam coming out of the exhaust on initial start-up. It's likely simply moisture that condensed since it last ran.
Coolant seal steam usually has a slightly sweet smell, pretty distinctive and you'd probably recognize it if present unless the previous owner ran almost all water. It's also almost always accompanied by other symptoms, most commonly a lumpy idle on cold start until the coolant burns off, coolant loss, air/gas in the system, an overflowing coolant overflow tank etc.

I believe its just running rich. The exhaust spits out water and carbon when I rev the car on a card start. The car runs strong and there are no symptoms. Thanks for helping me conclude what the issue was!

No offense meant....rev'ing the car cold, within reason, usually isn't a big deal. But know that with the rotary, it's always best to get the car up to operating temperature before any boost. The 'sandwich' construction of differing metals of iron and aluminum mean they will expand at different rates.
A little soot is common. Sounds like it was a safe tune. Which is a good thing IMO. And the street port may also contribute some to what your seeing...especially until warmed up.