Before using any flavoring with colors, I would at least suggest a quick google of the particular color/dye in the flavoring that you are considering.
Personally, I think the FDA has fallen-down on the job that it was intended to do, and, thus, I am leary of dyes/colors in general, without a personal research on the specific dye/coloring. I think some bad ones have flown under the radar and are on the market when they shouldn't be...
To do a google on a particular dye/coloring would only take maybe 2hr. total time and would either give you a little more peace of mind or assist you in selecting a different flavor.
Dyes/Colorings has always been my concern in the commercial liquids... If I cannot find a Bananna without coloring, then how are the manufacturers finding one? ...Because sometimes the dyes/colorings are added to bring stability to the flavoring.
Any rate, I haven't had time to personally research colorings and my fear of them dates way back to when my daughter was placed on a super restrictive diet of pretty much that she could only have/eat something if it was available in the same form as it was in the Garden of Eden. The diet was so restrictive we had to see a nutritionist to obtain a food list ... Back then, is when we were cautioned about bad dyes/coloring being on the market... but, honestly, I forgot everything that was told to us at the time. So, I would just do some personal research before I placed my health at possible risk.