Titanium Anodizer
Change color of any titanium part such as bolts, earings and more.
Need a variable power supply deppending of your needs. I have this from Aliexpress:
Algo need a titanium bar to use as a pointer, mine is 5mm diameter and as long as you want
The liquid needed to do the process is just water + Borax
The negative wire must be inside the little box and touching the liquid and the positive wire connected to the titanium bar and is what you will use to touch the piece you want to color.
You can see the process here: