Does all tea stain teeth?
I drink coffee, green tea and other herbal teas periodically and know that they stain your teeth but recently i've been drinking like 3-4 cups of Stash lemon ginger caffeine free herbal tea and don't see anything in ingredients that looks like it would stain teeth: ginger root, lemongrass, lemon flavor, safflower, hibiscus and citric acid. Can't help but think 3-4 cups might be too much and can't be good in some way or the other, am I over analyzing things?
Hibiscus is pretty dark, especially dried so that might stain (though I can't imagine nearly as bad as if you were drinking black tea).
What I'd be concerned about is the citric acid. It can wear away your enamel, and make your teeth more susceptible to staining from other things you eat.