What color tie should I wear with a purple shirt and charcoal suit?

Ender25
I'm going to be an usher in my friend's wedding. I've already been told that I'm to wear a purple shirt (per the bride), which I have (very similar to this: link )

I'm opting to wear a charcoal suit or medium gray suit

My questions are:

1) What color tie should I wear

2) Can I/Should I wear a vest, and if so what color for that?

I have a fair complexion and brown hair.
What color tie should I wear with a purple shirt and charcoal suit?
7 Opinion