I wrote a review for The Tranquil Parent about American Clay's colored plaster wall treatments. It's an interesting product, and if you're renewing an older home, I'd recommend taking a look at plaster as an alternative to paint, especially if you have chemical sensitivities of are concerned about off-gassing and VOCs. (Which, frankly, you probably should be). I especially like the Porcelina finish. Here's my take on it.