Masayasu Hiraoka, the man behind Mirco, was able to employ link "alumite" link treatment to achieve the unusual coloration. "Alumite" in Japan is also link known as "anodizing" elsewhere. It's a process where a layer of oxide is deposited on a metal, like the aluminum of the bezel insert on the Type-03, and it results in a color coating on the watch that also protects against corrosion and resists wear. In this application, the bezel is matched to the dial to create a uniform color theme.