Is the water color change due to materials being pulled through the pores of the feet?
The color change is a side effect of the process of ionization. It is caused by electrifying stainless steel in the array and that array coming into contact with the salt in the bath water. The ionization process causes the material on the array to break down and be released into the foot bath water and it causes the water and the minerals in the salt themselves to be shown in the water in the form of a brownish color.