This guide is for general information only and is not legal advice. Laws change — verify current rules with your state DOT or a licensed attorney before relying on this for any legal matter. Read full disclaimer.
The rule
Texas requires white headlamp visible from a distance of at least 500 feet to the front. For the rear, red reflector visible from 50 to 300 feet when directly in front of motor-vehicle low-beam headlamps, or a red rear lamp visible from 500 feet to the rear in lieu of the reflector. The rule applies whenever it is dark. See Tex. Transp. Code § 551.104(b).
The cheapest way to stay legal in Texas is a USB-rechargeable front white light and a rear red light or reflector that meets the spec above. A $30 light set covers it.