CHP Q&A

Whatever became of the law tha no motor vehicle, except police vehicles, could exhibit any kind of blue light to the rear? I don't recall if the prohibition related only to motorcycles or not, but I observe a lot of vehicles, especially big rig tractors, with bright blue lights visible from behind.

I remember as a kid my brother being cited for replacing the original red tail light lenses on his hot rod with Day Glow orange lenses which, when viewed from a certain angle, gave off a blueish-red cast.

Blue lights are not permitted on that vehicle. Vehicle Code section 25950 B:
(b) The emitted light from all lamps and the reflected light from
all reflectors, visible from the rear of a vehicle, shall be red
except as follows:
(1) Stoplamps on vehicles manufactured before January 1, 1979, may
show yellow to the rear.
(2) Turn signal lamps may show yellow to the rear.
(3) Front side marker lamps required by Section 25100 may show
yellow to the rear.
(4) Backup lamps shall show white to the rear.
(5) The rearward facing portion of a front-mounted double-faced
turn signal lamp may show amber to the rear while the headlamps or
parking lamps are lighted, if the intensity of the light emitted is
not greater than the parking lamps and the turn signal function is
not impaired.
(6) A reflector meeting the requirements of, and installed in
accordance with, Section 24611 shall be red or white, or both.
(c) All lamps and reflectors visible from the front, sides, or
rear of a vehicle, except headlamps, may have any unlighted color,
provided the emitted light from all lamps or reflected light from all
reflectors complies with the required color. Except for backup
lamps, the entire effective projected luminous area of lamps visible
from the rear or mounted on the sides near the rear of a vehicle
shall be covered by an inner lens of the required color when the
unlighted color differs from the required emitted light color.
Taillamps, stoplamps, and turn signal lamps that are visible to the
rear may be white when unlighted on vehicles manufactured before
January 1, 1974.

Thanks MICK1. I was fairly sure the law had not changed, but I see so many vehicles with blue lights visible from the rear I was beginning to wonder.

What I don't understand are the cars with blue lights installed in the windshield washer sockets. Guess I'm jut not cool.