Chemical coloring of metals

Chemical coloring of metals is the process of changing the color of metalsurfaces with different chemical solutions. According to David Fishlock:

"Basically there are only two methods of coloring a metal:

(1)By coating the metal with some other metal by means of such a process as electrodeposition

(2)By converting the metal surface into an oxide or salt which is colored or capable of absorbing coloring materials,or which produce color by interference."