Two are better than one.
Zinc is already the corrosion protection specialist per se. Because zinc is a material with a natural self-healing surface:
In time damage disappears of its own accord by means of the natural patination which visually corrects the damaged area. The corrosion protection is even more effective when two coats share the job between them.
Passivating, zinc-iron coating, tinning, chromium plating, gold plating, silver plating and nickel plating do a good job here.
We select the respective process based on your requirements. Incidentally, you don't have to do without a fine visual effect here either. Because depending on the process the surfaces have a a light bluish, iridescent in the colors of the rainbow, silver or golden sheen.