CHP Mustang emergency lights

[SparkSVT]

One of the members from .org made some pretty cool DVDs of Real Stories of the Highway Patrol. Im watching one that shows a CHP Mustang with the later lighting setup with the arrowstik and red-blue Federal Signal lights on the package shelf. They are chasing a car and I notice the only lights flashing on the Mustang are the blue lights and the last yellow on each side of the arrowstik. Seemed odd to me but thenI notice a second Mustang with the same flashing lights.. I would have thought the red and blues would flash alternately, not just the blue..I also never saw an arrowstik only flash the last two bulbs on each side like that.