For sure thank youAs in other states the only legal color for Fog Lights lights is white or yellow. Purple is not allowed anyplace for vehicle lighting. if they would be they would be useless for their original purpose. Take a look online and search for the actual law for CA but in general lighting is highly regulated for street cars.
I searched and found the following excerpt from the law:
California Vehicle Code section 25950 states, in part, “Unless provided otherwise, the color of lamps and reflectors upon a vehicle shall be as follows: (a) The emitted light from all lamps and the reflected light from all reflectors, visible from in front of a vehicle, shall be white or yellow, except as follows: (1) Rear side marker lamps required by Section 25100 may show red to the front. (2) The color of foglamps described in Section 24403 may be in the color spectrum from white to yellow … Any incidental visible light projecting to the front of the vehicle shall be predominantly yellow to white.”
Also see: Law section
Simple answer for CA specifically they are Illegal (and everywhere else).