I have had an adverse reaction to orange food coloring for more than 20 years.  After having episodes of vomiting, diarrhea, cold sweats and fainting for one year, I narrowed it down to foods that were artificially colored orange.  Avoiding artificial orange food coloring lessened the frequency of these episodes, but I continued to have them.  A friend suggested that Annatto might be the culprit.  I have closely monitored ingredient labels since, and have greatly reduced the number of these episodes.  If a product lists "and natural flavors," I put it back on the shelf.  A beta blocker was prescribed by my doctor to keep my heart rate in check, and the fainting has not occurred since - Jeanette (USA).