No, I think that rule has generally gone by the wayside. I think as a general rule, brighter colors would be the best to err on, and also consider the venue, the time of day, etc.
I wore a black dress to a friend's wedding, the little black dress. I did ask the bride if she was okay with it, though, because I was unsure of the appropriateness, and she was fine with it.
I wore this black dress in Tucson, AZ <<Waving to Bansidhe>>.
I spent half my life there! I'm surprised you say it wouldn't fly there.
Check with the bride if you're not sure. I'm sure it will be fine.