As a Red/Green color blind person I LOVE blue leds. They have mostly replaced the stupid Red/Green off/on indicator that I can't tell the difference between.
Now if only stop lights changed to "blue means go" we would live in a sane world. Picking two colors to mean opposite things (in life and death situations) that 5% of men can't tell the difference between is just a bit silly.
A simple solution for traffic lights would be to change the shape of stop lights to an octagon (matching the stop sign). This would be easy now they aren't a single bulb.
Could also change the amber light to a triangle.
Emergency, Fire and Police flashers are mostly blue by convention. Fire, not as much, unless volunteer.
Beyond that, I've always found green lights to be fundamentally, much brighter than any red lights. Tail lights and traffic lights don't shine through bedroom windows nearly as much as when traffic lights turn green. You can see the same effect in black and white photography, but then again, not all traffic systems are the same intensity.
I have a high powered LED flashlight, with a red low-light option, and I find the red LED nearly unusable. I think red, though, is usually a dimmer color than green, when it comes to lighting in the additive color model, and lighting elements.
It's reflective colors that present much less distinguishable differences.
I've noticed that myself (especially if there's a gas station nearby with a green-LED price sign). The green traffic light is, at least to my eyes, noticeably blue-green/aquamarine, where the gas station sign is emerald green.
Now if only stop lights changed to "blue means go" we would live in a sane world. Picking two colors to mean opposite things (in life and death situations) that 5% of men can't tell the difference between is just a bit silly.