Anodizing is an electrochemical process some jewelers use to change the color of metals such as titanium, aluminum, and niobium. Dipping a reactive metal into a "bath" mixture of low-sudsing ...

But this hack that shows you how to anodize titanium in your home laboratory ... and it’s possible to achieve a lot of different colors in the finish. In the image above [PinkFlute] is using ...

Which meant every tube was from a different batch, which meant they anodized differently ... is that the color can be a little different between 6/4 and 3/2.5 titanium, and any fluctuations ...