I think it's best to carry a red LED flashlight separate from your white light. It can be as simple as a keychain coin cell light and will still last a very long time. A red led produces red light directly, as opposed to a filtered white light which burns a lot of battery power making a full spectrum, then throws away 90% of the energy by filtering it. If you want something sturdier than a coin light, try a Gerber Infinity Ultra (red led version) which runs on one AA cell. There is also the new LRI Proton (
www.photonlight.com) which has six white leds and one red led, runs on one AA, and is dimmable (microprocessor controlled), a good general purpose light though on the pricey side for non-flashlight buffs.