A recent video captures the color changes that a titanium bar experiences during the process of anodization. Kottke writes: “Anodizing is an adjustment of the oxide levels on the surface of the titanium. The colors are caused by the interference of the light traveling through the oxide and reflecting off the shiny metal surface underneath — different thicknesses produce different colors. As the voltage is applied to the metal, more and more oxide builds up, producing the color cycling even shown. Pretty cool!”