Common question, unfortunately the MCU would have to stay awake, consuming more battery, and also on at least some if not all of the common MCUs, there aren’t enough PWM waveform generators to do it with aux anyway. For lights I may need quickly in the dark, I usually set locked aux to either white or disco.
The real solution is full RGB aux so people can choose what they want, of course 
My aluminum TS10’s are split between blue and green aux. All of my Hanklights are set to voltage, and usually blue as well. I’ve found that the only colors that affect my night vision are orange and yellow, which ruin it the same way 2700-3000K does. I spent too much time doing night-ops on carriers to buy all the hype about red, though it’s a better fit for copper than a cooler color would be. The blue goes real nice with silver though, and is also what I’m used to seeing on the bridge at night.
I think there are two different kinds of considerations re: aux color: utility, and aesthetic. I was referring to the former, and you to the latter – so I guess both of us could be right.
When I first got my TS10, my idea was to try and use its red aux for illumination on very dark situations, but it proved useless for that, even on high mode: the way the way the aux LEDs are positioned behind the non-focusing parts of the optics make then totally diffuse.
In the last few days, I’ve started using them for locating purposes: I used to leave my light in a very specific location by the bedside so as to be able to find it in the dark, but that frequently failed; with my TS10 red auxes on low, this problem has been solved and they’re non-intrusive enough not to disturb my sleep.
100% agreed. Wurkkos once reported they were working on that (on Reddit IIRC) for a future edition of the copper TS10 (again IIRC). @Wurkkos_Terry, any progress on that?
Interesting, and totally contrary to my experience, for me anything non-red ruins my night vision and disturbs my sleep, even at low intensities. Case in point, I tape over any and all non-red LEDs in electronics around the house even away from the bed because if I wake up for a fridge or potty run, they disturb me enough to make it hard getting back to sleep. The same happened with my FC13 as a bedside lamp, in voltage-showing mode which is usually blue or green, it was completely disturbing and I had to turn the switch away from me, and it ended up being replaced by the TS10 for that function.
I guess it’s really different strokes for different folks! 
Got it my man! We are designing the new PCB for real RGB TS10 now ; )
Yay!!! Great news, can’t wait! Please post here in this thread when it’s available, otherwise please '@'tag me when you do!
I agree Red is best for sleep
Blue is best for staying awake
Yay!
Just in time for the Titanium model
There is a Poll Here about the surface finish. So far Shiny and Stonewashed are most popular…
I hope more people will vote…
Thanks for the heads-up, I haven’t seen that poll, just went there and voted.
I will definitely buy a TS10 with controllable-RGB auxes, and would sure like to have it in non-aluminum metal (copper or titanium) depending on price.
Agree
Some sort of variable resistor would solve both problems. Of course it would use PCB real estate, but one of these perhaps could fit: https://www.robotics.org.za/TRIM-1K-SMD
Even better would be a digitally controllable resistor; I know they exist from a project I did many years ago, but they were large and expensive – not sure if that has changed.
One thing this hobby and working optometry/optical has taught me is how variable human vision really is.
Red shines right through eyelids while blue does not.
Interesting! But I just checked it and (at least with my FC13 RGB switch LED on low intensity) both blue and red are visible with my eyelids closed, and with the same perceptible brightness.
Perhaps there’s some mutation to block blue light in one’s eyelids, and I missed getting it in the genetic roulette?
Red light wavelength scatters much less, so theoretically red indeed shines more through eyelids than blue. That’s why sunset is red.
It could be that I got freak eyelids or that Blue LEDs are just more intense/visible than red ones… but indeed adapting to total darkness and then turning on my FC13 switch LED first with blue and then red in front of my closed eyes showed the same apparent luminosity.
Let’s all agree on this then: the best for sleep and nightvision is dim light.
For night vision, one interesting thing is that the center of the vision (where the eyes focuse and can make out details and colors) is less sensitive to low light thaln the periphery. You can see a very dim light by looking right besides that light.
In astronomy we call it “averted Vision”. For seeing dim objects you would look outside of the central part of focus.
It works!
I was going to post exactly that but you beat me to it As it is, I can only add that it usually allows one to see at least a magnitude weaker objects that direct, focused vision.
Are you an amateur astronomer too?
I have been into it for many years. I have lots of equipment. Not very active these days. My trees have grown so I can’t see much of the sky from my yard now. Packing up driving 1.5 hours to a dark site, and setting up makes me much less likely to observe these days. But I still read a lot and keep my Sky and Telescope subscription in place…
Traditionally everyone used red. People would get upset when anyone used anything else. So I used red.
I read a similar article to the one you linked several years ago. I got some green lights to use at home. I liked them better for reading sky charts. I can’t say that my eyes actually did better with green or not.
So my opinion, I will use green when I can avoid conflict over its use.
Brilliant!
thanks for your thoughts
tangents
Green attracts more mosquitoes than Red
Deer and Hog hunters believe those animals are less likely to spook w those colors, than w white light. Green is preferred for seeing Hogs because their dark coats dont show up well w Red.
Red Plus Green combined are best for tracking blood.
Red does not reduce the sleep hormone Melatonin. Green reduces the sleep hormone.
I can see a LOT better w Green than w Red. And I see even better w white light… lol
