Sensient came through for us. They've got regular old fashioned caramel coloring, as well as new natural alternatives that will not trigger proposition 65 warnings. If people don't know, there's a legal issue in California that requires a warning label if you have certain chemicals in your product that carry more than an allowable amount. The chemical is:
"4-methylimidazole (4-MeI), an impurity and potential carcinogen created during the manufacturing of caramel coloring, in various soft drinks. Because 4-MeI is a potential carcinogen, and identified as such under California’s Proposition 65 law, any food or beverage sold in the state that exposes consumers to more than 29 micrograms of 4-MeI per day is supposed to carry the Proposition 65 warning."
Apparently Coke and Pepsi contain a lot of this because there's a lot of caramel coloring in sodas. Much less in our product, but finding a local lab to analyze for 4-Mel has been challenging. The alternative coloring agents from Sensient don't have quite the effect of caramel coloring and aren't as stable, so there's still more research for me to do. I'll let you know what I find out.