I built my safelight using an amber led module of 12 or 16 leds, it worked great and spectrally was an almost perfect match for an OC filter. I can't remember the manufacturer, it have been Luxeon.
I have been using Polybrite's M60 red, which has a bigger bulb than the S11. Five years leaving it on day and night. The only time I shut it off is when I am working with film.
These LED bulb looks promising to me both in Red and Amber. Might have to give them a try they are cheap enough and the give spectral graphs of the colors.
I use these (red or amber, depending on the paper type). I put them in a small clamp-on housing, hang them from the rafters about 10 feet from the trays, and bounce them off the white walls. I tested them with a couple papers when I first got them but didn't have any fogging after 10 minutes so I stopped.
I bought a $30 4' tracklight at lowes. About 5' over the enlarger or tray, it puts out a bright red spot about 2' in diameter. I might make something to diffuse it a little bit more. It is so bright, I can read typewritten text even at floor level. It's like having restaurant heat lamps in the darkroom except it puts out zero heat. I tested a piece of Ilford MGIV with steps for upto 4 minutes as it's the fastest paper I have (The warmtone is slower), and developed it extra long and saw absolutely nothing on the paper. It is amazing how bright you can have these and not fog paper. I have one beaming on the developer tray and I can watch the highlights developing on prints. You don't want one of these LED lights bare aimed right at the enlarger easel as it's so bright it will make it hard for you to focus/compose. Aim it off to the side or diffuse it a little bit.
In addition to these two LED lights on a tracklight, I have a big old amber Kodak safelight on the ceiling as pictured. So the darkroom is a much brighter place than needed. If I order more stuff from dealextreme sometime, I'll get an extra bulb and aim the third can that came with the tracklight into the wash tray so my daughter can have plenty of light to play in the water while I work.
Maplins sell mains voltage LED lamps rated at 1.8 watts. Problem is they are on a GU10 fitting and so far as I can find you can't get a bayonet to GU10 adapter to allow easy fitting to a bayonet socket. So I bodged a couple onto old bayonet fittings (don't think you can get them now either) and put them in my 2 Kodak Beehives. Didn't have the nerve to do without the orange filters already there so I put them back in. Gives a more directional light which I have tested and found safe with max-flashed Ilford MG paper for 10 minutes on the enlarger baseboard, about 6 feet from the nearest beehive.
Maplins used to quote a wavelength for these lamps which come in several colours but I notice in my latest catalogue, now a year old, that they no longer do, though they do for other LEDs.
I have just located Bayonet Cap to GU10 adaptors on Amazon - they come from HongKong, very cheap. I have seen several LED bulbs on the links in this thread, but they all seem to be Edison Screw. So I have ordered a couple of the adaptors. As I noted above I bodged amber LEDs into Kodak beehives but have kept the rather ancient amber filters in, to diffuse the light which is otherwise rather directional, and, as I now have found out, to suppress those random spikes of other wavelengths.
And apropos the bulbs seen in links, some of them have orange or red glass globes - are they white LEDs with coloured glass? Because that is not the same as an amber LED - or is it?
Richard
I made a safelight with many very deep red LEDs. The effect is probably like Ken's LEDs plus Rubylith. It allows a high light level, but as someone noted above, it's not the most pleasant light in which to work. In addition, I now use a home made amber LED safelight for short inspections towards the end of development. It is so much better on the eyes, and near the end of development for a short time has no deleterious effects.