See Norm's post above. Not the one where he says I think the no-white after Labor Day is still in force in Key West.
White is perfectly acceptable on a cruise to warm climates. And I mean white shoes, dinner jackets, or anything else.
I remember my dad grumbling every spring and fall because he had to change dinner jacket colors. He was so not the fashion plate. But, I thought he looked fabulous whatever he wore. Mom just kept him on the socially acceptable path.