Hi, ellen I am following, but In the middle of changing apartments so it will take time to give a proper answer.
The document by @MichelleVandepoele givesa good initial overview, and itpoints out that indeed itmight be ecofriendly just not in the way people outside the business, think ecofriendliness works. (less watercost and higher recycling incentive, rather than easily disposable)
It will take me sometime to get familiar with the literature.
also when we use food dyes we typically skip the mordant phase. a mild mordant, might make a big difference.