My DS age 3 (sensory seeking) is affected by food dye. It seems to trigger a lot of the behaviors and change something in his brain. I saw this when he was a baby and I was nursing and eating things like yogurt, gum, granola bars, etc that had dye and he would take hours to go to sleep and just scream and kick for hours. I refuse to let him have any of the regular kid type treats with dye, even at Halloween and parties. If you've identified it, way to go. There can be so many ups and downs, if you notice one thing that you can control to prevent those challenging things, then it certainly makes it a lot easier.