Seriously. Everybody's wearing white. You don't think that at least 20% of the guests will wind up with some wildly conspicuous food blemish smack dab in the middle of their outfits? While pretty much all food will inflict some sort of damage when bombing white fabric, a dish like grilled shrimp with lemon zest won't do anywhere near as much damage as bean burritos with habanero salsa. Don't plan the menu around items' stain-averse qualities, just be aware that spillage could be a buzz-kill for clumsier guests.