I would have to get the box but they are natural occuring dyes (i think that is why they have them in limited colors) but dont have red dye number 5 and such in them. I think of it as the natural dyes used back in the day for fabrics, probably blueberries, and other strong colored fruits. Yes there are many poisioness plants but these are for baking so I know they are not harmful.
I got them for making cakes and such since I do the organic thing and will swear that the chemical dyes in foods cause my son to become fussy and cranky and the natural dyes dont. I avod all foods with red dye in them since there have been studies to this effect.