Subie

Given how you are describing your requirements, think about looking at the lights made for weapons (google "tactical lights"). They tend to be very bright, and some will have filters for different applications. Surefire is one of the major manufacturers serving the tactical (police and military) market, but there are others.

I have SIG SAUER's STL-100C, (http://www.sigsauer.com/SigStore/ShowProduct.aspx?categoryid=26) and it is bright enough to sear your retinas. That one didn't come with any filters.

I've also seen some cool lights made by Gerber that had little LEDs, with a rotary filter on the front.

Alternately, you can go down to WalMart and pick up anything that MagLite makes for anywhere from 7-50 bucks. The smaller lights will have filters that you can take on and off, but they are not as convenient as a light with different color LED bulbs. They are, however, cheap, and can put out a lot of light.

Just be warned: just as with any other peice of gear, if you want small, light, and good (in this case, bright) you will pay a premium for it.

Sincerely

Steadman