Titanium can be anodised to give many vibrant colours.  Titanium is anodised using an electrolysis process; this process adjusts the oxide level on the surface of the metal. This change in the oxide level controls the light refraction and therefore the colour of the surface metal. By carefully adjusting the oxide level you can control the colour of the metal surface.

The surface colour of the anodised product is an integral part of the metal product, not a coating, and is just as bio-compatible.