Much like crew of the Starship Enterprise, the roles played by employees at Apple Retail stores will be identifiable by the color of their shirts.
Now, before you confuse the guys in blue shirts for science officers and those in red for security, we'll explain how it's going to work. According to a post at ifoAppleStore, Geniuses and Creatives will wear dark blue. Specialists will wear light blue, and the Concierge will wear orange.
Also, orange shirts will bear the slogan, "I know people," while the dark blue will read, simply, "Business." Finally, the crew in the back room will wear the traditional black T-shirt, assuming the role of the guy you don't recognize in an away team who's sure to die.
One must imagine that the Concierge will console irate customers by offering them Earl Grey tea "...in my ready room."