Yesterday I ordered a set of 16 food colors because my granddaughter has an (apparently not uncommon) neuro sensitivity to red dye 40. GD has ADHD (as do I, my brother, and my sons, but not her mother, i.e., my daughter). The dye exacerbates her ADHD, really revving her up and making it difficult for her (or anyone within 10 yards of her) to sleep.
As she gets older, her sensitivity increases. After an evening of cookie decorating - and eating - last Saturday, it hit her pretty hard (and I feel terrible about that.) DD called Sunday morning asking me to check my food colorings. Sure enough - red dye 40 was listed in the ingredients. My existing 30+ food colors will hit the trash when these arrive.