I took part in some testing for Four4th when they were developing the green LEDs – comparing the green LEDs and the standard LEDs back to back.
I found the green LEDs gave better definition and less glare back off the trail. They were particularly good in the twilight period before it is fully dark where I tend to find standard LEDs struggle a bit.
Funnily enough –
I find halogen headlights easier to see by than modern discharge or LED.
– they felt somewhat halogen-like in this respect (albeit unsurprisingly far more powerful than my ancient halogen light). The beam colour is warmer than standard LEDs, it seems more yellow than green when projected onto the terrain (which is largely green anyway) – although looking directly at the LEDs they are definitely green!
Most other riders doing the test seemed to agree, although one rider who needs fairly strong glasses felt the opposite, so they are not for everyone. Four4th do have demo sets you can try so it is well worth contacting them to find out.
As others have said, mixing a green helmet light with a standard bar light or vice versa doesn’t really give much benefit, so if you are supplementing an existing light then bear this in mind.
I’m not claiming to be unbiased as I race for Four4th so obviously I would recommend the lights, but when it came to choosing green vs standard (with my own money!), I went for green without hesitation.
Hope that helps, but if you’ve got any questions then just give Four4th a shout, Del is happy to chat at length about this kind of stuff.