[Beastmaster]

Here's the laws involving it.

Texas Transportation Code 547.305 and 547.702
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§ 547.305. RESTRICTIONS ON USE OF LIGHTS. (a) A motor
vehicle lamp or illuminating device, other than a headlamp,
spotlamp, auxiliary lamp, turn signal lamp, or emergency vehicle or
school bus warning lamp, that projects a beam with an intensity
brighter than 300 candlepower shall be directed so that no part of
the high-intensity portion of the beam strikes the roadway at a
distance of more than 75 feet from the vehicle.
(b) Except as expressly authorized by law, a person may not
operate or move equipment or a vehicle, other than a police vehicle,
with a lamp or device that displays a red light visible from
directly in front of the center of the equipment or vehicle.
(c) A person may not operate a motor vehicle equipped with a
red, white, or blue beacon, flashing, or alternating light unless
the equipment is:
(1) used as specifically authorized by this chapter;
or
(2) a running lamp, headlamp, taillamp, backup lamp,
or turn signal lamp that is used as authorized by law.
(d) A vehicle may be equipped with alternately flashing
lighting equipment described by Section 547.701 or 547.702 only if
the vehicle is:
(1) a school bus;
(2) an authorized emergency vehicle;
(3) a church bus that has the words "church bus"
printed on the front and rear of the bus so as to be clearly
discernable to other vehicle operators;
(4) a tow truck while under the direction of a law
enforcement officer at the scene of an accident or while hooking up
to a disabled vehicle on a roadway; or
(5) a tow truck with a mounted light bar which has turn
signals and stop lamps in addition to those required by Sections
547.322, 547.323, and 547.324, Transportation Code.
(e) A person may not operate highway maintenance or service
equipment, including snow-removal equipment, that is not equipped
with lamps or that does not display lighted lamps as required by the
standards and specifications adopted by the Texas Department of
Transportation.
(f) In this section "tow truck" means a motor vehicle or
mechanical device that is adapted or used to tow, winch, or move a
disabled vehicle.

Acts 1995, 74th Leg., ch. 165, § 1, eff. Sept. 1, 1995. Amended
by Acts 1999, 76th Leg., ch. 380, § 1, eff. July 1, 1999.

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§ 547.702. ADDITIONAL EQUIPMENT REQUIREMENTS FOR
AUTHORIZED EMERGENCY VEHICLES. (a) An authorized emergency
vehicle may be equipped with a siren, exhaust whistle, or bell:
(1) of a type approved by the department; and
(2) that emits a sound audible under normal conditions
at a distance of at least 500 feet.
(b) The operator of an authorized emergency vehicle shall
use the siren, whistle, or bell when necessary to warn other vehicle
operators or pedestrians of the approach of the emergency vehicle.
(c) Except as provided by this section, an authorized
emergency vehicle shall be equipped with signal lamps that:
(1) are mounted as high and as widely spaced laterally
as practicable;
(2) display four alternately flashing red lights, two
located on the front at the same level and two located on the rear at
the same level; and
(3) emit a light visible at a distance of 500 feet in
normal sunlight.
(d) A private vehicle operated by a volunteer firefighter
responding to a fire alarm or a medical emergency may, but is not
required to, be equipped with signal lamps that comply with the
requirements of Subsection (c).
(e) A private vehicle operated by a volunteer firefighter
responding to a fire alarm or a medical emergency may be equipped
with a signal lamp that is temporarily attached to the vehicle roof
and flashes a red light visible at a distance of at least 500 feet in
normal sunlight.
(f) A police vehicle may, but is not required to, be
equipped with signal lamps that comply with Subsection (c).

Acts 1995, 74th Leg., ch. 165, § 1, eff. Sept. 1, 1995.