I'll have a rummage about to see if I can find anything useful, red and (as I remember amber) have a far lower Vf than the Newer green/blue/white.
Okay, forget what I just said about green.
I just dug out three Kingbright "Extreme Brightness" 5mm LED's (Red, yellow, green, water clear, untinted case in all examples) and set my power supply to 2.4v, stuck a resistor in there to restrict the total current to 50mA, and hooked the LEDs up, the result came out looking as follows:
NOTE: Beamshot was taken from a distance of ~1 foot with the LED's simply stuck in a protoboard, no reflectors, optics or other fancy things used.
Green seems to be a slight bit brigther to the eye, but the red would be better for night vision preservation if that were an issue, and would probably give you light for longer as the batteries run down.
(That pic actually shows accurately how it appears to the eye for once! Finally getting my head around this camera)
Not sure where else there are available, but I know they can be found at
Maplin Electronics (Where I got these from)
Part Numbers:
Red = "N69AJ"
Orange = "N70AJ"
Yellow = "N71AJ"
Green = "N72AJ"
£0.49 (~ US $0.60) each.