I would suspect that it does more than just light up with that one color. Different conditions or settings would probably activate just the blue or just the orange. Possibly options you don;t have in the car this came from, but are available, or maybe something that isn't frequently encountered. I can't imagine they would ever use a dual color LED just to make other other color that is readily available as a simple LED.
Frankly - if this is on the side facing the driver, I would NEVER use a white LED, it's distracting and more harmful to night vision than other colors.