Actually, I'd have to disagree with the idea that it must be dark red and it must be 4 feet away. I have insanely bright red and yellow LED bulbs (OptiLED) and they both seem to be safe for all papers. I bought both colors since I thought papers like Slavich would need it. I routinely use them both for lith printing (development up to 10 minutes) without fogging. LEDs are nice because they act over a very narrow wavelength band.
I really don't think that was particularly big disaster you describe. Now when you fog an entire box of paper for the second or third time......let's just say that I've invested in multiple paper safes!