Food coloring has to be declared doesn't it?
Well, i went hunting around for some marshmellows the other day and found these:
Corn Syrup, Sugar, Modified Food Starch (Corn), Dextrose, Water, Gelatin, Natural And Artificial Flavor, Tetrasodium Pyrophosphate.
The kraft version had blue food coloring in it. These don't appear to have them in it.