My last couple of cruises (Panama Canal & Hawaii) I noticed a number of men wearing the 'white' dinner jacket w/ Tux pants. etc.
On the Hawiian trip I took both a black Tux dinner jacket and the white dinner jacket. The same pants, shirt, tie, cummerbund and shoes are worn with both. On a cruise with 3 or more formal nights it gives one a chance for a different look.