Section 25258 Of Article 7. Flashing And Colored Lights From California Vehicle Code >> Division 12. >> Chapter 2. >> Article 7.

. (a) An authorized emergency vehicle operating under the conditions specified in Section 21055 may display a flashing white light from a gaseous discharge lamp designed and used for the purpose of controlling official traffic control signals.
  (b) An authorized emergency vehicle used by a peace officer, as defined in Section 830.1 of, subdivision (a), (b), (c), (d), (e), (f), (g), or (i) of Section 830.2 of, subdivision (n) of Section 830.3 of, subdivision (b) of Section 830.31 of, subdivision (a) or (b) of Section 830.32 of, Section 830.33 of, subdivision (a) of Section 830.36 of, subdivision (a) of Section 830.4 of, or Section 830.6 of, the Penal Code, in the performance of the peace officer's duties, may, in addition, display a steady or flashing blue warning light visible from the front, sides, or rear of the vehicle.
  (c) Except as provided in subdivision (a), a vehicle shall not be equipped with a device that emits any illumination or radiation that is designed or used for the purpose of controlling official traffic control signals.