Chewing Gum

How come chewing gum doesn't lose its color?  I was chewing on piece of Extra Spearmint, and that stuff was bright green for a least an hour of use - and you know that color isn't natural. I propose that a piece of chewing gum is placed in a ball-milling machine with some sort of saline solution as the lubricant.  After ball-milling for a long time, the lubricant can then be tested from emission / excitation - one would expect to see the wavelength of the gum's color, and this could be then used to get an idea of the amount of color that leaches from the gum. And that's my grocery shopping thought of the day!