I am a teacher and we did an observational activity in which we placed salt and food coloring on a big piece of ice. We observed it using a flashlight for awhile. Afterwards when we turned the lights on the salt with RED food coloring had a beautiful green glow. I have searched but cannot find an answer to why this occurs. Hope you can help.

I don't know the answer but this phenomenon must be caused by the high concentration of NaCl. My best guess is that the salt and dye have reacted to produce a chloro complex of the dye (or simply raised the ionic strength to HIGH levels) and the green glow is a reradiation similar to phosphorescence. If you discover the answer we would be interestd in hearing about it. Thanks for posting on Jiskha.