the different colored waters may possibly be caused by contaminants already present in the water or from the electrodes.
but this does not detract from the efficacy of the footbaths.
the initial technology was created by nikola tesla, ( he was aware even at the turn of the century that the world was becoming more and more polluted)one of the smartest people to have ever existed. if you could somehow aggregate the entire intelligence of the thousands of people on curezone, it would still be less than nikola tesla's.
i have tried them myself. they definitely do work as advertised. in fact i was surprised that they are actually stronger than i had imagined.
the bfe model was developed for use by the australian army as a field detox unit. too many credible sources to overlook. too much money in anti-science debunkery these days.