These earrings are 100% niobium - a hypoallergenic metal that is non-irritating for even the most sensitive ears. Niobium is a reactive metal - element #41. It's called "reactive" because if you pass an electrical current through it, the surface of the metal changes color. In its raw state, it's a shiny grey metal - very similar in appearance to stainless steel. But if you heat it or run electrical current through it, the color of the surface changes dramatically. There are no dyes involved, the colors you see on niobium are purely a natural property of the material (with a bit of a "boost" from some salt water and voltage). I use electricity to anodize my niobium rings because it gives better control and the results are cleaner.