On my boat I have a rear facing round 6 x 3 watt 12v floodlight attached to the cabin roof to light up the deck & the water behind the boat during night fishing.
It is very bright (to bright really) & illuminates well but destroys our night vision.
I was wondering about doing something so it puts out red not white light.
I cannot find a red coloured lens cover the right diameter to fit the light & was wondering that if I put a red film over the lens that that would do the trick ?
If so any ideas on a suitable film to use ?
Do you now anbody that works in theaters?
If not, pop in a theater during the day and ask for the technician.
They use all sorts of films in all sorts of colors and if you have a nice “click” with the technican you might just walk out with some cut offs (do bring your cool flashlights, all these technicians I know love that kind of stuff and before you know it you’ll be walking on the bridges at ceiling height where all the lamps hang and shine around with him both with a smile from ear to ear)
I have had a PM suggesting I use a translucent red spray paint made specifically for colouring clear lenses.
As the lens on my floodlight is not smooth but rather bumpy (pronounced orange peel) then I think that his suggestion of spraying rather than sticking a film on makes sense.
I can then build up layers until I reach the colour I want 
And when your cometa and C8s are in please visit a theater off hours, you are bound to have great fun (I never met a technician who was not a bit crazy about lights and buttons in those places.)
If you go to a show check the bar during intermission or after, you’ll likely to spot a black simple clothes wearing person with leather man hanging on his (or her) belt, ask how many LEDs they are now using if any and you are in for a nice conversation)
I’m not sure but I think there are legal regulations regarding permanently mounted red or green light colors on boats and ships which you may run afoul of with this. Best to check with your local Marine Authorities first.
Phil