We had hot pink, hard sided luggage. During the 2010 Christmas Blizzard when we camped a LaGuardia airport we had to get our bags, recheck our bags, reclaim our bags, etc., it made it very easy to spot our luggage in a sea of black bags.
One of my favorite convention give aways is the luggage tag made with my laminated business card on one side and books in multiple languages on the other. I went, 'Huh! Smart!' and switched all the luggage tag inserts to my business card. My home address isn't flashed around and if a bag needs to be delivered someone is at the library many times when I'm not home.