This is an option with aluminium nameplates. It is an electrolytic passivation process that makes the natural oxide layer thicker on the metal’s surface. With this process, a durable finish and also prevent the metal from corroding the nameplate.
With anodising, various colours for the decorative finish. Black, blue and red are all colours that can be effectively produced through anodising. But choose clear anodising if you would prefer to keep a silver look, or select a different hue altogether.