I wanted a white metal because I'd always wanted an antique-style ring and I just think they look "right" in white gold or platinum.
When I was looking for my ring
(one of the benefits of a trans-Atlantic relationship--I was allowed to pick my own ring!), I stumbled across THE PERFECT ring...it was an estate piece--a lovely blue diamond set in platinum with an etched setting studded in little diamonds. The only problem was that it cost more than my car....or my entire college education, for that matter!
Still, I visited it until it was sold.
Then I mourned. :\\\'(
Then one day a few months later, I saw the "perfect" ring's twin (or close enough!) and I had to have it immediately! I called DH and begged him for it and he sent me a cheque--sight unseen!
The best part was the price--I got exactly what I wanted, but for about a tenth of the "perfect" ring's cost.
Anyway, I now realize I've gone off on a tanget.
I was going to say that you should make sure that you get your wedding and engagement rings at the same time, from the same dealer. My engagement ring was new, but my wedding band was an antique. As a result, the wedding band is a slightly different colour of white gold. It's not terribly noticeable, but
I know about it. I need to take it in to get in dipped in rhodium, but I never remember to do it!