I get this with my wife - she's gold (on various airlines), I'm nothing or silver at best, but I'm Caucasian and she's not. I get on the plane and settle down in my seat unmolested, but for her, "Ma'am, this is Business Class, you can't sit here" is the usual greeting on BA, LH and LX. Once when travelling solo in LH First, she was taken to the plane in FRA from the First Class terminal by a driver, and when they arrived at the plane, with the driver carrying her luggage, the purser greeted the driver at the door, asked my wife to step aside as a First Class passenger was now coming though, and then asked the driver "where's he gone now?" ("wo ist er denn jetzt?"). Hilarity ensued.