I have discovered (I think) why the flavors change colors for some and not for others. I made a batch of Cake for a friend and put it in a clear glass bottle. Within a day, it turned a light orange. The batch of Cake I made for myself in an amber glass bottle stayed clear. I think these flavors change color when exposed to light. Food for thought.
That makes sense but I think it is more the nicotine that is effected. I've made 3 bottles now of the same exact flavorings and the one I left sitting out on my counter turned pink while the two I had in my steep box stayed pretty much clear.
Also I made two bottles with two different nicotine's, one from RTS (turned pink) and one from VZ (turned yellow) with the same flavoring's at the same strength.