Polish it first. Get it to its final state including clear coat.
Then typically its two stage color then silver chrome.
From the inside... with an airbrush... super fine & light mist of color. Let that cure. Then same with a quality chrome like Alclad II.
But since you want that gold-chrome... You might be able to locate a gold chrome to do in one application instead of a color/chrome 2 stage.
Remember you can always add more - but its not so easy to take it away if you go heavy: Basically you have to strip and repaint.
And practice the heck out of your technique first: Don't let the actual visor being your learning tool.
You can find clear plastic to practice on just about everywhere - any piece of plastic blister packaging can work for practicing on, so you can get a feel for how much paint gets you an acceptable level of clarity:mirror balance.
