Blue On Blue Offender: The inexplicable phenomenon in which someone chooses to wear blue jeans with a blue shirt of the same or similar shade of blue. Most often occurs with rednecks wearing their jean shorts (more commonly referred to as Jorts) and NASCAR or band t-shirts. B.O.B.O.'s will also most likely finish their ensemble with black socks, a fanny pack or trucker hat, and mullet or rat-tail.
Hey, check out the B.O.B.O. over there. I wonder where he parked his IROC-Z28.