I wish I had an answer- it's kind of something I'm trying to figure out myself at the moment too. My tongue is definitely more yellow than white. The candida is MUCH better (hence no white) but I am suffering from adrenal exhaustion (from having been too stressed, I've tired out my adrenal glands). I think that this excessive heat in your body (caused by stress) is indicated by the yellow tongue. That's all I've really discovered. The tongue is often considered a map of your stomach, when it's yellow it indicates damp heat. In my case, I'm sure the night sweats/adrenal/stress thing is connected. I imagine plenty of cooling foods will help but I really am at the same stage myself so if you have any thoughts or suggestions, do let me know I'd be very interested.