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In general, however, black-tie doesn't mean black, and colour is usually welcome as long as the silhouette feels formal enough (floor-length dresses would be a safe bet)

Pants: Color= Black

Models height:5'6"

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But yes, I agree Richard, and as mentioned in the piece I think keeping more classic black tie for some events (eg weddings in the US, more serious things) would be good, we dont want to lose that