do you have an airbrush?
there are quite a few options in the modelling world ie Mr Color's Super Metallic
https://www.youtube.com/watch?v=FC-FLFGx_pk
plenty of other videos on youtube
one thing to note is that these paints are (relatively) quite expensive, a small 10ml bottle would cost like $5 to $10, while one bottle should be more then enough to paint a lightsaber, but I wouldn't recommend that for a life size Captain Phasma build
don't have any experience with the automotive spray cans, but I have seen some that claims to be chrome as well.