There are many techniques for adding color and metal.
Powder Coating
Is applied electrostatically as a powder to metal and then cured under heat to create a hard colorful finish. It is commonly used for coating household appliances and automobile and bicycle parts.
Resin
I use a two part epoxy resin and add pigment to create various colors. Before the resin cures it is poured into metal vessels.
Anodizing Aluminum
Aluminum
Patinas
There are