I'm not a chemist and I'm looking for a simple bistable and reversible electrochemical reaction that changes color, specifically:
- A liquid in a glass with two electrodes that when a voltage is applied, the liquid changes color.
- When the power is removed, the new color remains (at least for a few minutes/hours).
- When an opposite voltage is applied, the liquid changes to the original color and stays like that when power is removed.
- It's possible to repeat this process many times without having to replace the electrodes.
It would be ideal if the chemical components were easy to get and non-toxic. The colors don't matter at all (transparent to red, blue to green, orange to white, anything really).