Got a petzl mirco which is powered by aa batteries .Cheap shops have led
head torches for a £5 .and ever ready do for £9 which does red and white light quite good and not a drama when you break it lose it .
Agreed - 10 of those will last you a long time and only cost you £10.
a Square metre of red lighting gel (it's not actually 'gel', its coloured plastic!) will cost you a few quid, cut out a nice circle and stick it on with some superglue and you have one with a red filter and one without for about £3 total.
Alternatively, you can get a headstrap for maglite AA torches. This means you can always take it out and use it as a normal maglite should you want to do that. Red filters for those are about a quid from army shops. If you're going down this route, buy the LED conversion for the torch, it makes it much better. It's only 3 LEDs, which IMO is a bit more practical, as whilst those headtorches with 25 LEDs in mean you can see everything within a square mile of you, it means when you're looking for your teddy bear in your bergen and somebody says your name, you looking at them causes them to lose vision for the next 10 minutes... which may lead to fists flailing blindly in your general direction.