Tie Color Recommendation for a Groom

My sister is getting married and her future husband refuses to wear a Tux and a bow tie, he wants to wear a black suit, a white shirt and and tie.

What color tie should he wear? I was thinking of suggesting him to wear a black tie. What other options there are for this formal event?
He is white and has blue eyes and dark hair.

Here in Romania we have a triple part wedding: City Hall (in the morning – close family only), Church (in the afternoon – extended family + some friends) and Reception (in the evening – all the guests), should he wear the same color tie for all these tree parts of the wedding?