Seriously, would this not be the most efficient option? I've been using a red LED safelight bulb, with a pretty bandwidth of light.
My darkroom needs a good coat of paint, and I was considering going grey, as in the 18% greycard, in order to neutralize reflections but, if I went with full red, I should get close to 100% reflectance of the good (safe) light while reducing reflectance of unsafe wavelengths down to a minimum. All this assuming that I'm concentrating on B&W work. Any thoughts?
But when you turn the white room lights on, everything will look red. I want to see my prints as black and white, not black and pink! I also think grey would be pretty gloomy under both safe and white lights.