Teeth question

So my teeth have been pretty messed up but theyve finally got their caps on and they look the most normal theyve looked in a year.

Anyway I really don't want to start the process again especially as they're so painful and my dentist said if they even hurt a tiny bit I need to take the caps off, I was wondering is there a way to whiten caps? Without damaging them???

It's the metal on with white on.

I mean I would leave it but it's my two front teeth and I'm Ngl they are yellow af and look weird next to my other teeth