Does CA have unmarked cop cars with lights and sirens?

[ShadowSe7en]

The lights were blue and yellow flashing lights and were mounted inside the vehicle, on the passenger side, near the top of the windshield. As it passed me, I could also hear a siren. It exited northbound CA-17 at Hamilton Avenue.

Does CA have unmarked police vehicles that use lights and sirens like that?

Are flashing blue and yellow lights considered an emergency vehicle in CA? In my state blue and yellow are DOT or road maintenance. Emergency vehicles here have to either be red or red and blue lights to the front of the car.