Tux question

My fiancé is into possibly wearing a dark grey tux/suit to our wedding, but my sister the MOH is wearing a light grey silverish dress. Is that going to look good because they are sort of matching? Or should he stick with a black one?

Tux question - Long Island Weddings

See if you can bring a swatch of either the tux to the dress shop or the dress to the tux shop and look at them side-by-side. If you don't have swatches, you can always bring a picture to the shops and ask the opinion of the people there. They're professionals that do this every day and they tend to know what will look good.