My Convoy (chosen with help of the good folk on here) arrived yesterday.
I like it a lot. Took the dog for a walk and it fits it’s purpose (almost) perfectly.
One thing very noticeable and disappointing is the beam. It seems to have a lot going on. When walking the dog, I noticed pink and purple rings on the outer part of the beam, seems like a defect? Looks very weird to me.
For reference, I went with the 2700k SST20 6*7135 smooth reflector.
Any feedback appreciated…
Odd. Never saw an S2+ with that kinda beam.
The glass has an anti-reflective coating, that causes a pinkish tint around the edges. It’s probably possible to find the same size glass without the coating. The AR coating lets more light though, but it’s probably not a huge difference.
You can just remove the AR coating using aluminum oxide polishing paste (the same used to car polishing). It’s very easy to unscrew the pill. Just be careful with dust and never touch the reflective surface of the reflector.
With the flashlight off, use the lens as a mirror to look at a light bulb in your house and the bulb will have that purplish pinkish color. Not all AR coated lenses will reflect that purplish pinkish though as some will be a light blue, some will have no color. I have plenty of different brands of lights with that purple pinkish reflection and some with blue and some with no color. I have a convoy s2+ sst20 2700k from when they first came out and it has a light blue coating and you don’t see a ring. But I have an SST 4000k with the purple pink coating and I see that ring. You don’t really see it in normal use unless you are looking at White Walls. There has been some reference in other posts about a coating on only one side and obviously some lights don’t have a coating but it seems most get coated on both sides.?? And possibly some reference to why some people see a greenish tint with some LEDs back when slicing them was popular being related to the AR coating.
It’s also possible you’ve got a tiny bit of light reflecting off the bezel itself - I’ve noticed a ring from this on a few lights I own. What color S2+ is it?
What can help is to put the light on its lowest mode, line your eyes up with the rings, and look back at the light to see what it’s reflecting off of.
It’s the grey coloured one. Find it distracting in use.
Tried that with the bulb and can see it reflects a pink colour.
Found it quite distracting when walking the dog, like a pink/purple half ring on the ground in front of me.
Then close your eyes 
S2+ sand brown with Xpl hi 3000k and a very noticeable purple pink ring. So it’s not related to light off of the bezel. Slight p/p ring on a few other lights. Once you know what it is you can stop looking at it.
If you want a lens without the coating they are available. The size is 20.5mm x 1.6mm. Banggood has them here
I recently got my purple S21A with a KW CSLPM1.TG emitter. It has a really cool purple halo just outside the spill circle. It matches the color of the anodizing very nicely.
I thought it might just be the emitter since it’s my first with that one. Maybe not, though.
Almost any light with AR coating will have something like this. Personally I don’t mind it at all but would prefer lenses without this (poorly performing) AR coating only because it can make tint more greenish.
My guess is it’s the smooth reflector and maybe the anti reflective coating on the lens but like burning play doh says .. the uV lens usually makes tints green not purple .
First thing to do is take it apart and run it without the lens and see if that makes a difference . Second try with a decent diffuser ,then try without lens and reflector. Then try with no lens or reflector and diffuser film . You could raise or lower the emitter height in the reflector too but that’s going to be harder and probably isn’t causing the.ring or tint shift .?
I don’t know for sure but my guess is that an sst20 is always going to be a hard emitter to tame . A throw emitter always has some tougher issues and my guess is people are unwilling to design a reflector just for one somewhat pesky emitter . ...Emitters change so quickly these days IDK just a thought . I’ve seen some emitter /reflector combinations in the past that made me appreciate Fenix for marrying the two together in an amazing way.
The sst- 20 4000k is a crazy cheap way to grab high cri but imho it takes at least a 1/8th minus green Zircon Lee filter to fix the tint ...and if the beam pattern bugs you or if you want a smoother more pleasant beam then I add Dc-Fix diffuser film too.
As a good flashlight junkie I simply opted for two convoy S2’s .. one with a filter ...and one with Dc-fix
actually it’s more like 6 sst-20 s2’s but who’s keeping track .
I might try some of the suggestions about removing lens etc, if I’m feeling brave.
As other people have the same issue, at least I know I didn’t get a dud.
No you’re absolutely right, it does make the tint more green (as duv measurements have shown many times), but what’s happening is that the spectrum of light that the lens is reflecting most is for some reason reflected or refracted to the sides when that is the color of the AR coating. It’s the same way blue mirrored sunglasses give an amber/orange tint from the wearer’s perspective: whatever color you’re reflecting therefore has being transmitted through the lens. Purple/magenta artifacts/relfections = a beam with less of that color, hence relatively more green
I have no idea what the reason is but I do know that results is an artifact FAR past the edge of the spill and it has happened in all but one AR-coated lens light I have owned. Different color AR coatings even have different colored artifacts of course! 
I see the same thing on my Convoy S2+ SST40. I suspect it’s because of the glass AR-coated.