I found this website with links to laws regarding automotive vehicles (including motorcycles) for most of the 50 states.
Motorcycle lighting laws Wyked Illuzionz Frederick Maryland
For Alabama, I believe I found as detailed as it get's regarding all motor vehicles in...
Chapter 5 REGULATION OF OPERATION OF MOTOR VEHICLES, ETC., GENERALLY
Section 32-5-241 Additional permissible lights on vehicles.
(1) Any lighted lamp or illuminated device upon a motor vehicle other than head lamps, spot lamps, auxiliary lamps, or flashing front direction signals which projects a beam of light of an intensity greater than 300 candlepower shall be so directed that no part of the beam will strike the level of the roadway on which the vehicle stands at a distance of more than 75 feet from the vehicle.
(2) No person shall drive or move any vehicle or equipment upon any highway with any lamp or device thereon displaying a red light visible from directly in front of the center thereof. This section shall not apply to authorized emergency vehicles.
(3) Any vehicle may be equipped with flashing lamps which may be used for the purpose of warning the operators of other vehicles of the presence of a vehicular traffic hazard requiring the exercise of unusual care in approaching, overtaking, or passing, and when so equipped may display such warning in addition to any other warning signals required by this section. The lamps used to display such warning to the front shall be mounted at the same level and as widely spaced laterally as practicable and shall display simultaneously flashing white or amber lights, or any shade of color between white and amber.