[SilverY2KCivic]

Here's some interesting bits taken from the Californis Vehicle Code...

24252. (a) All lighting equipment of a required type installed on a vehicle shall at all times be maintained in good working order.
Lamps shall be equipped with bulbs of the correct voltage rating
corresponding to the nominal voltage at the lamp socket.
(b) The voltage at any tail, stop, license plate, side marker or
clearance lamp socket on a vehicle shall not be less than 85 percent
of the design voltage of the bulb. Voltage tests shall be conducted
with the engine operating.
...(1) No turn signal lamp may be combined optically with a stoplamp
unless the stoplamp is extinguished when the turn signal is flashing.

25102. In addition to the lamps otherwise permitted by this
chapter, any motor vehicle may be equipped with lamps on the sides
thereof, visible from the side of the vehicle but not from the front
or rear thereof, which lamps, together with mountings or receptacles,
shall be set into depressions or recesses in the body of the vehicle
and shall not protrude beyond or outside the body of the vehicle.
The light source in each of the lamps shall not exceed two
candlepower and shall emit diffused light of any color, except that
the color red is permitted only on authorized emergency vehicles.

25106. (a) Any motor vehicle may be equipped with lighted white or
amber cowl or fender lamps on the front. Any vehicle may be equipped
with not more than one amber side lamp on each side near the front,
nor more than one red side lamp on each side near the rear. The
light source of each such lamp shall not exceed four standard
candlepower.
(b) Lamps meeting requirements established by the department for
side-marker or combination clearance and side-marker lamps may be
installed on the sides of vehicles at any location, but any lamp
installed within 24 inches of the rear of the vehicle shall be red,
and any lamp installed at any other location shall be amber.

24608. (a) Motortrucks, trailers, semitrailers, and buses 80 or
more inches in width manufactured on or after January 1, 1968, shall
be equipped with an amber reflector on each side at the front and a
red reflector on each side at the rear.

24400. During darkness, every motor vehicle other than a
motorcycle, shall be equipped with at least two lighted headlamps,
with at least one on each side of the front of the vehicle, and,
except as to vehicles registered prior to January 1, 1930, they shall
be located directly above or in advance of the front axle of the
vehicle. The headlamps and every light source in any headlamp unit
shall be located at a height of not more than 54 inches nor less than
22 inches.

24402. (a) Any motor vehicle may be equipped with not to exceed two
auxiliary driving lamps mounted on the front at a height of not less
than 16 inches nor more than 42 inches. Driving lamps are lamps
designed for supplementing the upper beam from headlamps and may not
be lighted with the lower beam.
(b) Any motor vehicle may be equipped with not to exceed two
auxiliary passing lamps mounted on the front at a height of not less
than 24 inches nor more than 42 inches. Passing lamps are lamps
designed for supplementing the lower beam from headlamps and may also
be lighted with the upper beam.

24403. (a) A motor vehicle may be equipped with not more than two
foglamps that may be used with, but may not be used in substitution
of, headlamps.
(b) On a motor vehicle other than a motorcycle, the foglamps
authorized under this section shall be mounted on the front at a
height of not less than 12 inches nor more than 30 inches and aimed
so that when the vehicle is not loaded none of the high-intensity
portion of the light to the left of the center of the vehicle
projects higher than a level of four inches below the level of the
center of the lamp from which it comes, for a distance of 25 feet in
front of the vehicle.

24405. (a) Not more than four lamps of the following types showing
to the front of a vehicle may be lighted at any one time:
(1) Headlamps.
(2) Auxiliary driving or passing lamps.
(3) Fog lamps.
(4) Warning lamps.
(5) Spot lamps.
(6) Gaseous discharge lamps specified in Section 25258.
(b) For the purpose of this section each pair of a dual headlamp
system shall be considered as one lamp.
(c) Subdivision (a) does not apply to any authorized emergency
vehicle.

I couldn't find any provision that mentions about headlight color emitance, so that's all on the officer or patroling city I think and their interpertation of what's considered legal and not.

You can look up further Cali Vehicle Codes here.

Hope that helps some of you guys out at least with legalities reguarding lights on cars in CA.