You are correct and just for $hits and giggles I looked up the actual info for Texas.
Sec. 547.305. RESTRICTIONS ON USE OF LIGHTS.
[…] (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.
But hey. It looks like laws these days are sort of like "The Pirates Code". Just a set of more like guidelines than actual laws.