You can also get a right-angle Army flashlight on Ebay for about $4 bucks.
These come with different color filters (including RED) concealed in the bottom of the handle.
They also come with a belt clip, a pull-out hanger, and can be stood on their base for hands free lighting.
They also have a "signal" button you can press for instant on-off glimpses when you only need a quick look.
For use as a regular flashlight, the filter can be easily removed and stored in the base.
I got one because it had so many more features than the expensive astro flashlights advertised that aren't as versatile.
Welcome to Altair4 gentlemen. We have two moons, a beautiful green sky, and we are only 16 light years away. Come visit anytime.