I would like to try this stuff again, but with new set expectations. I can't use this stuff for full opaque coloring, but I would very much like to try it for highlighting and adding depth to other colors.
I did a search to see what the interwebz said about this stuff:
Edible Food Coloring NEW & IMPROVED! in a Aerosol can. Shake can, hold at a 45 degree angle, spray 6-8" away from item. One can covers more than a dozen 8" cakes plus dozens of cookies, sugar and fabric. This is a wide spray; if a thin line is required use stencils.More than a dozen 8" cakes, hmm? Perhaps I'm not spraying close enough. I was about 8" away. I found a few reviews by an obvious plant, Freak369, who suggests spraying it on cardboard and different distances for the desired color control.
One can will cover approx. (6) 8" round cakes, (4) 9" X 13" cakes or (4) dozen cupcakes