If you decide to go the flashlight route you can also check your army/navy surplus store for a decent military flashlight. I still have mine from boot camp in 96 and it still works. It comes with the red and blue removeable filters and the head sits at a 90 degree angle. Their small and have a clip so you can slip it onto your belt when you dont need to hold it. Mine takes 2 D batteries to give you an idea of the size of the flashlight.
edit: Just checked mine, the lens holder on the bottom contains a red lens, blue lens, a white lens(think its purpose is the same as the green, as i couldnt see the light on the wall from 2 ft with it in), a clear lens and a clear patterned lens which seems to disperse the light better so its not just a strong centered beam on the ground but a wider beam. Of course I'm missing my red filter but 3 extra on top of the clear one currently in use is pretty good imo.
